Z line, n.

z-line
http://www.oed.com/dictionary/z-line_n%3Ftab%3Dmeaning_and_use
First published 1986; not fully revised

# Z linenoun

## Earlier version

- Z line in OED Second Edition (1989)

## Factsheet

### What does the noun Z line mean?

There is one meaning in OED's entry for the noun Z line. See ‘Meaning & use’ for definition, usage, and quotation evidence.

#### Entry status

OED is undergoing a continuous programme of revision to modernize and improve definitions. This entry has not yet been fully revised.

### How common is the noun Z line?

About 0.08occurrences per million words in modern written English

1910 | 0.0061
1920 | 0.0087
1930 | 0.021
1940 | 0.036
1950 | 0.053
1960 | 0.062
1970 | 0.07
1980 | 0.076
1990 | 0.086
2000 | 0.086
2010 | 0.075

### How is the noun Z line pronounced?

#### British English

/ˈzɛd lʌɪn/
ZED lighn

#### U.S. English

/ˈzi ˌlaɪn/
ZEE lighn

### Where does the noun Z line come from?

Earliest known use

1910s

The earliest known use of the noun Z line is in the 1910s.

OED's earliest evidence for Z line is from 1916, in a text by Jordan and Ferguson.

Z line is formed within English, by compounding.

Etymons: Z n., line n.2

### Nearby entries

1. zizel, n. 1775–
2. zizypha, n. 1546–1775
3. zizyphus, n.?1440–
4. zizz, v. 1883–
5. zizz, int. & n. 1824–
6. zizzing, n. 1884–
7. zizzing, adj. 1919–
8. zizzy, adj. 1843–
9. Zlid, n. 1616–1785
10. Z'life, n. 1689
11. Z line, n.1916–
12. Z-list, n. & adj. 1979–
13. Z-lister, n. 1999–
14. zloty, n. 1915–
15. Zn, n. 1814–
16. -zoa, comb. form
17. -zoan, comb. form
18. zoantharian, adj. & n. 1887–
19. zoanthid, n. 1870–
20. zoanthidan, adj. 1888–
21. zoanthodeme, n. 1877–

## Etymology

### Summary

Formed within English, by compounding.
Etymons: Z n., line n.2
< Z n. + line n.2, partial translation of German schicht z z layer (T. W. Engelmann 1873, in Arch. f. die ges. Physiol. VII. 37), < initial letter of zwischenscheibe intervening disc.

## Meaning & use

Histology.

1. 1916–
   A transverse dark line in a fibril of striated muscle formed by Krause's membrane (see Krause n. b); the membrane itself.
   1. 1916

      > This stripe or accessory disk..bisects the portion of the J disk between the Z line and the succeeding Q disk.

      Jordan & Ferguson, Text-book of Histology iv. 105
   2. 1954

      > The series elastic component is provided either by the actin filaments themselves, or, more probably, by their mode of attachment to the Z-line.

      Nature 22 May 976/1
   3. 1979

      > In muscle fibers the actin filaments are anchored to flat protein structures called Z lines, which are emplaced between every two contractile units.

      Scientific American May 94/2
   anatomy physiology
   1. well a1400–25
      Surgery. A hollow between muscles or tendons, esp. one used as a site for cautery; = fontanelle, n. 1a. Obsolete.
   2. fontanelle?a1425–1541
      Anatomy. A natural hollow on the surface of the body, typically one located between two muscles or tendons. Cf. well, n.¹ II.7. Obsolete.
   3. head?a1425–
      The upper or principal extremity of various things, esp. when projecting, distinct, removable, or of… Anatomy. The end of a muscle that remains…
   4. belly 1591–
      The bulging part e.g. of a pot or bottle; a suddenly widened part of a vein of ore; the central portion of a muscle, etc.
   5. venter 1615–1728
      Anatomy. (See quot. 1728.) Obsolete.
   6. tail 1719–
      A thing, part, or appendage, resembling the tail of an animal in shape or position. The attenuated part of a muscle at its insertion.
   7. myotome 1857–
      Embryology and Zoology. A part of the embryonic mesoderm which gives rise to the skeletal muscles; each of the metameric segments of this. Also…
   8. sclerotome 1857–
      A sclerous element intervening between successive myotomes.
   9. myomere 1868–
      Each of a series of blocks of mesodermal tissue situated on either side of the spine in vertebrate embryos; (also) each of the muscle blocks…
   10. muscle spindle 1894–
       A fusiform bundle of specialized muscle fibres with sensory and motor innervation enclosed in a capsule of connective tissue, present in large…
   11. spindle 1894–
       Anatomy. = muscle spindle, n.
   12. Z line 1916–
       A transverse dark line in a fibril of striated muscle formed by Krause's membrane (see Krause, n. b); the membrane itself.
   13. Z band 1950–
   14. dyad 1957–
       Anatomy. A structure found in vertebrate cardiac muscle and some insect muscle, consisting of a transverse tubule in contact with a terminal cisterna…
   15. triad 1957–
       Anatomy. A structure found in the striated skeletal muscle of most vertebrates, which consists of a transverse tubule of the T-system in contact…
   View in Historical Thesaurus
   1. aponeurosis 1676–
      A white, shining, fibrous membrane, sometimes serving as the sheath of a muscle, sometimes forming the connection between a muscle and a tendon.
   2. myolema 1840
      = sarcolemma, n.
   3. sarcolemma 1840–
      The fine transparent tubular sheath investing muscular fibre.
   4. perimysium 1842–
      The connective tissue or fascia that forms sheaths around bundles of muscle fibres in a muscle and around the muscles themselves.
   5. myolemma 1873
      = sarcolemma, n.
   6. Z line 1916–
      A transverse dark line in a fibril of striated muscle formed by Krause's membrane (see Krause, n. b); the membrane itself.
   7. Z band 1950–
   8. sarcoplasmic reticulum 1953–
      Of, pertaining to, or containing sarcoplasm; sarcoplasmic reticulum, the characteristic endoplasmic reticulum of striated muscle.
   View in Historical Thesaurus

## Pronunciation

### British English

/ˈzɛd lʌɪn/
ZED lighn

### U.S. English

/ˈzi ˌlaɪn/
ZEE lighn

####

##### Consonants

- ppea
- ttea
- kkey
- bbuy
- ddye
- ɡguy
- tʃchore
- dʒjay
- ffore
- θthaw
- ssore
- ʃshore
- vvee
- ðthee
- zzee
- ʒbeige
- xloch
- hhay
- llay
- ɬrhingyll
- rray
- wway
- jyore
- mmay
- nnay
- ŋsing

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.

View the pronunciation model here.

####

##### Consonants

- ppea
- ttea
- kkey
- bbuy
- ddye*
- ɡguy
- tʃchore
- dʒjay
- ffore
- θthaw
- ssore
- ʃshore
- vvee
- ðthee
- zzee
- ʒbeige
- xloch
- hhay
- llay
- rray
- wway
- jyore
- mmay
- nnay
- ŋsing

* /d/ also represents a 'tapped' /t/ as in

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.

View the pronunciation model here.

####

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

## Frequency

Z line typically occurs about 0.08 times per million words in modern written English.

Z line is in frequency band 3, which contains words occurring between 0.01 and 0.1 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 Z line, n., 1910–2010

* 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
--- | ---
1910 | 0.0061
1920 | 0.0087
1930 | 0.021
1940 | 0.036
1950 | 0.053
1960 | 0.062
1970 | 0.07
1980 | 0.076
1990 | 0.086
2000 | 0.086
2010 | 0.075

Z line, n. was first published in 1986; not fully revised.

Z line, n. was last modified in July 2023.