There are six meanings listed in OED's entry for the adjective zealous, one of which is labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence.
How common is the adjective zealous?
About 2occurrences per million words in modern written English
1750
26
1760
24
1770
23
1780
23
1790
24
1800
24
1810
25
1820
25
1830
23
1840
22
1850
19
1860
16
1870
13
1880
11
1890
9.3
1900
7.5
1910
6.1
1920
5.0
1930
4.3
1940
3.7
1950
3.3
1960
3.0
1970
2.5
1980
2.0
1990
1.8
2000
1.8
2010
1.9
How is the adjective zealous pronounced?
British English
/ˈzɛləs/
ZEL-uhss
U.S. English
/ˈzɛləs/
ZEL-uhss
Where does the adjective zealous come from?
Earliest known use
Middle English
The earliest known use of the adjective zealous is in the Middle English period (1150—1500).
OED's earliest evidence for zealous is from around 1495, in the writing of R. Fitzjames.
<post-classical Latinzelosus ardent, fervent (5th or 6th cent. designating an emotion, 7th cent. designating a group of people) <classical Latinzēluszealn. + ‑ōsus‑oussuffix.Compare earlier jealousadj. and…
<post-classical Latinzelosus ardent, fervent (5th or 6th cent. designating an emotion, 7th cent. designating a group of people) <classical Latinzēluszealn. + ‑ōsus‑oussuffix.Compare earlier jealousadj. and the Romance forms cited at that entry.
Characterized by or indicative of passionate enthusiasm or fervour for a cause, belief, objective, etc. Cf. zealn. 2.
?1495
An helper or sauer of ye people by his holy & zelose obedyence.
R. Fitzjames, Sermo Die Lune in Ebdomada Pasche (de Worde) sig. avi
1541
When they had spoken, the emperour and other that were with hym, semed to commende their zelous affection.
T. Elyot, Image of Gouernance f. 98v
1563
The many meanes, wherby I dyd bewraye My zelous wyll, to earne my prynces grace.
W. Baldwin et al., Myrrour for Magistrates (new edition) Hastings xiv
1597
When..religious men, Are at their beads, tis hard to draw them thence, So sweet is zealous contemplation.
W. Shakespeare, Richard IIIiii. vii. 94
a1616
This zelous kisse.
W. Shakespeare, King John (1623) ii. i. 19
1649
Then which [sc. Bulla Cruciatæ] there was never a more zealous piece, published to the world.
Bishop J. Hall, Resolutions & Decisionsii. iii. 130
1756
That You may soon return safe & well to this Kingdom is ye most Zealous Wish of Yr most devoted D: Garrick.
D. Garrick, Letter 26 February (1963) vol. I. 237
1808
To those doctrines he expressed a zealous attachment.
W. Wilson, History Dissenting Churchesvol. I. 391
1852
Zealous and intelligent co-operation.
W. E. Gladstone, Functions of Laymen in Church 36
1902
Efforts that are as hasty as they are zealous.
Davenport (Iowa) Daily Republican 9 March 10/2
1958
George's plain and morally zealous strictures on the inequities of private land-holding..served to stir a mass interest in the ‘land question.’
American Political Science Reviewvol. 52 904/2
2003
The duty of a lawyer to provide zealous representation.
R. G. Madden, Essent. Law Social Workers iv. 63
1.b.
1582–1641
† Characterized by or expressive of intense or powerful emotion, esp. when directed at the preservation or protection of something; ardent, vehement; righteously passionate. Cf. zealn. 1. Obsolete except as merged in sense 1a.
1582
Godlie and zealous anger in the husband towards the wife is lawfull.
T. Bentley, Sixt Lampe Virginitie 17
1590
Whenas the noble Britomart heard tell Of Troian warres..She was empassiond at that piteous act, With zelous enuy of Greekes cruell fact, Against that nation.
E. Spenser, Faerie Queeneiii.ix. 538
1608
The People fall In zealous fury on the Priests of Baal.
J. Sylvester, translation of G. de S. Du Bartas, Deuine Weekes & Workes (new edition) ii. vi. 98
1641
When hee saw his Fathers House abus'd..hee had anger certainly, though not as a passion of revenge..it was zealous anger, not vicious anger.
M. Milward, Sword-bearer 13
2.
Of a person, group, etc.: fervently or passionately devoted to a cause, belief, undertaking, etc.; vehemently or earnestly dedicated to the pursuit of an objective or outcome. Also (esp. in later use) in weakened sense: eager, keen (cf. zealn. 3).
2.a.
1526–
With the object towards which zeal is directed introduced by for or of (formerly also over, to, unto, etc.). Now somewhat rare.
1526
They are all zelous over the lawe [Geneva zelous of the Lawe].
Bible (Tyndale) Acts xxi. 20
1535
I haue bene zelous for the Lorde God Zebaoth.
Bible (Coverdale) 1 Kings xix. 10
1611
I..was zealous towards God.
Bible (King James) Acts xxii. 3
1644
Jerom..though zealous of single life more then anough,..defended Fabiola.
J. Milton, translation of M. Bucer, Ivdgement concerning Divorce 6
1733
Be assured that none is more truly zealous for your welfare, than your F. A. Kelly.
in Swift's Letters (1768) vol. IV. 47
1824
His Ministers, zealous of the royal interests.
Morning Chronicle 28 December
1849
The House of Commons..more zealous for royalty than the king, more zealous for episcopacy than the bishops.
T. B. Macaulay, History of Englandvol. I. ii. 175
1908
Many new converts..were zealous of good works.
New Castle (Pennsylvania) News 29 July 10/4
1963–4
The Ministry of Education is most zealous of maintaining direct control of all educational policies and practices.
International Rev. Educationvol. 9 434
2014
It's possible to be simultaneously enthusiastic about language, zealous for good English teaching and..hostile to the philosophy behind the Bad Grammar Awards.
In attributive or predicative use without construction.
In the 17th cent., sometimes with disparaging implication of excessive puritanical zeal (see quot. 1673); cf. zealn. 2.
1545
Zelouse wolde this Poete fayne be seane in his holye mothers quarell.
J. Bale, Mysterye Inyquyte P. Pantolabus f.55v
1551
Cause a zelous Phinees to shedde the harte bloude of hym that that..taketh a Madianite into hys tent.
T. Lever, Serm. xiiii. December (new edition) sig. E.viv
a1591
As some giddy spirites thinke now, that they which are zelouser than themselues know not what they say nor doe.
H. Smith, Sermon (1592) 921
1617
Let them stay at home who are so zealous, as they will pull the Hostia or Sacrament out of the Priests hand.
F. Moryson, Itineraryiii. 32
1659
Out of the ablest and zealousest among them to create elders.
J. Milton, Considerations touching Hirelings 90
1673
Are they not reverend botchers,..or some weavers, Some zealous cobblers, hatmakers and glovers?
J. Wade, Vinegar & Mustard (1873) 15
1700
When I see the Authors so very zealous in defending their own Mistakes..I cannot but extreamly regret the ill usage of those important Truths they undertake to confute.
A. B., Letter to Friend 3/1
1776
We had divers large and good meetings in that city, there being considerable body of sensible zealous friends.
Short Journal Labours & Trav. D. Bell (new edition) 80
1874
Episcopacy had become identified among the more zealous Scotchmen with the old Catholicism.
J. R. Green, Short History of English People viii. §5. 508
1888
Zealous in whatever he undertook, truthful and sincere, he made the Tribune a paper of vast and healthy influence.
H. McCulloch, Men & Meas. of Half Cent. xxxiii. 494
1921
A zealous patriot..and one, too, with the courage of his convictions.
Bakersfield Californian 27 June ii. 8/1
1945
Success in weather forecasting depends on adequate scientific observations and an adequate staff of zealous workers.
Times 3 August 5/6
2009
Several people felt that prosecutors..were overly zealous in pursuing indictments.
L. S. Chancer in D. Humphries, Women, Violence, & Media xii. 263
3.
1545–
Esp. of God: fiercely or passionately protective or vigilant in the preservation of something; jealous. Cf. zealn. 1a, jealousadj. 3, 4. Now rare or merged in sense 2.
1545
I am the strong and zelouse God.
G. Joye, Exposicion of Daniel (i.) f.12
1563
To spoyle the zelous God of his honour.
2nd Tome of Homelyes Agst. Idol. iii. sig. Tt ij b
1630
That this people should be so wonderfully zealous of the renowne of their nation.
G. Hakewill, Apologie (ed. 2) iv. x. 433
a1720
This holy and zealous God, will, when he marks Iniquity, surround himself with the most piercing Light.
W. Dunlop, Sermon (1722) vol. II. 67
1890
Those people were so zealous of their rights, that they were not willing to accept that Constitution without a Bill of Rights.
Convent. Rec. (Kentucky Constit. Convent.) 15 October 12/2
1955
A nation, so obsessed with the political and cultural superiority of its neighbors, yet so proud and zealous of its own accomplishments.
Hispanic Reviewvol. 23 211
2014
A zealous God who accepts nothing that does not recognize the glory of his holiness.
Some consonants can take the function of the vowel in unstressed syllables. Where necessary, a syllabic marker diacritic is used, hence /ˈpɛtl/ but /ˈpɛtl̩i/.
Vowels
iːfleece
ihappy
ɪkit
ɛdress
atrap, bath
ɑːstart, palm, bath
ɒlot
ɔːthought, force
ʌstrut
ʊfoot
uːgoose
əletter
əːnurse
ɪənear
ɛːsquare
ʊəcure
eɪface
ʌɪpride
aʊmouth
əʊgoat
ɔɪvoice
ãgratin
ɒ̃salon
ᵻ(/ɪ/-/ə/)
ᵿ(/ʊ/-/ə/)
Other symbols
The symbol ˈ at the beginning of a syllable indicates that that syllable is pronounced with primary stress.
The symbol ˌ at the beginning of a syllable indicates that that syllable is pronounced with secondary stress.
Round brackets ( ) in a transcription indicate that the symbol within the brackets is optional.
Some consonants can take the function of the vowel in unstressed syllables. Where necessary, a syllabic marker diacritic is used, hence /ˈpɛd(ə)l/ but /ˈpɛdl̩i/.
Vowels
ifleece, happy
ɪkit
ɛdress
ætrap, bath
ɑlot, palm, cloth, thought
ɑrstart
ɔcloth, thought
ɔrnorth, force
ʊfoot
ugoose
əstrut, comma
ərnurse, letter
ɪ(ə)rnear
ɛ(ə)rsquare
ʊ(ə)rcure
eɪface
aɪpride
aʊmouth
oʊgoat
ɔɪvoice
ɑ̃gratin
æ̃salon
ᵻ(/ɪ/-/ə/)
ᵿ(/ʊ/-/ə/)
Other symbols
The symbol ˈ at the beginning of a syllable indicates that that syllable is pronounced with primary stress.
The symbol ˌ at the beginning of a syllable indicates that that syllable is pronounced with secondary stress.
Round brackets ( ) in a transcription indicate that the symbol within the brackets is optional.
Simple text respell breaks words into syllables, separated by a hyphen. The syllable which carries the primary stress is written in capital letters. This key covers both British and U.S. English Simple Text Respell.
Consonants
b, d, f, h, k, l, m, n, p, r, s, t, v, w and z have their standard English values
gguy
jjay
yyore
chchore
khloch
shshore
ththaw
dhthee
zhbeige
Vowels
atrap
ahpalm
airsquare
arstart
arrcarry (British only)
awthought
ayface
a(ng)gratin
edress
eefleece
eerdeer
errmerry
ikit
ighpride
irrmirror
olot (British only)
ohgoat
oogoose
oorcure
orforce
orrsorry (British only)
owmouth
oyvoice
o(ng)salon
ustrut
uhletter
urnurse
urrhurry
uufoot
Forms
Variant forms
α.
(a)
late Middle English; 1600s
zelose, zelous
1500s
zeleus, zelowse
1500s–1600s
zelouse
(b) Also Scottish
pre-1700
zelios, zelois, zelus
β.
(a)
1500s–
zealous
(b) Also Scottish
pre-1700
zealus
Frequency
zealous typically occurs about twice per million words in modern written English.
zealous is in frequency band 5, which contains words occurring between 1 and 10 times per million words in modern written English. More about OED's frequency bands
Frequency data is computed programmatically, and should be regarded as an estimate.
Frequency of zealous, adj., 1750–2010
* Occurrences per million words in written English
Historical frequency series are derived from Google Books Ngrams (version 2), a data set based on the Google Books corpus of several million books printed in English between 1500 and 2010.
The overall frequency for a given word is calculated by summing frequencies for the main form of the word, any plural or inflected forms, and any major spelling variations.
For sets of homographs (distinct entries that share the same word-form, e.g. mole, n.¹, mole, n.², mole, n.³, etc.), we have estimated the frequency of each homograph entry as a fraction of the total Ngrams frequency for the word-form. This may result in inaccuracies.
Smoothing has been applied to series for lower-frequency words, using a moving-average algorithm. This reduces short-term fluctuations, which may be produced by variability in the content of the Google Books corpus.
Decade
Frequency per million words
1750
26
1760
24
1770
23
1780
23
1790
24
1800
24
1810
25
1820
25
1830
23
1840
22
1850
19
1860
16
1870
13
1880
11
1890
9.3
1900
7.5
1910
6.1
1920
5.0
1930
4.3
1940
3.7
1950
3.3
1960
3.0
1970
2.5
1980
2.0
1990
1.8
2000
1.8
2010
1.9
Frequency of zealous, adj., 2017–2024
* Occurrences per million words in written English
Modern frequency series are derived from a corpus of 20 billion words, covering the period from 2017 to the present. The corpus is mainly compiled from online news sources, and covers all major varieties of World English.
Smoothing has been applied to series for lower-frequency words, using a moving-average algorithm. This reduces short-term fluctuations, which may be produced by variability in the content of the corpus.