zenith distance, n.

zenith-distance
http://www.oed.com/dictionary/zenith-distance_n%3Ftab%3Dmeaning_and_use
Revised 2018

# zenith distancenoun

## Factsheet

### What does the noun zenith distance mean?

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

### How common is the noun zenith distance?

About 0.07occurrences per million words in modern written English

1750 | 0.29
1760 | 0.3
1770 | 0.29
1780 | 0.32
1790 | 0.48
1800 | 0.43
1810 | 0.48
1820 | 0.51
1830 | 0.51
1840 | 0.53
1850 | 0.51
1860 | 0.4
1870 | 0.35
1880 | 0.33
1890 | 0.31
1900 | 0.29
1910 | 0.27
1920 | 0.25
1930 | 0.22
1940 | 0.2
1950 | 0.17
1960 | 0.14
1970 | 0.12
1980 | 0.089
1990 | 0.071
2000 | 0.047
2010 | 0.036

### Where does the noun zenith distance come from?

Earliest known use

late 1500s

The earliest known use of the noun zenith distance is in the late 1500s.

OED's earliest evidence for zenith distance is from 1588, in a translation by A. Ashley.

### Nearby entries

1. Zener, n.¹ 1934–
2. Zener, n.² 1949–
3. Zengakuren, n. 1950–
4. Zen garden, n. 1937–
5. zenick, n. 1801–1900
6. zenitfer, n. 1596–
7. zenith, n. & adj. a1387–
8. zenithal, adj.?1731–
9. zenithal projection, n. 1877–
10. zenith-borne, adj. 1865–86
11. zenith distance, n.1588–
12. zenith line, n. 1585–
13. zenith point, n. 1585–
14. zenith sector, n. 1775–
15. zenith sweep, n. 1790–
16. zenith telescope, n. 1803–
17. zenith tube, n. 1825–
18. zenithward, n., adv., & adj. 1655–
19. zenithwards, adv. 1826–
20. Zenker, n.¹ 1872–
21. Zenker, n.² 1894–

## Meaning & use

1. 1588–
   The angular distance of a celestial object from the zenith (the complement of its altitude or angular distance from the horizon).
   1. 1588

      > For if the declination be Southward, it must be subducted from the Zenithes distance: but if Northward, added.

      A. Ashley, translation of L. J. Wagenaer, Mariners Mirrour sig. B2
   2. 1658

      > Get the sum and difference of half the Suns Zenith distance at the hour of six.

      J. Collins, Sector on Quadrant 243
   3. 1704

      > Zenith Distance, is the Complement of the Sun, or Stars Meridian Altitude, or what the Meridian Altitude wants of 90 Degrees.

      J. Harris, Lexicon Technicum vol. I
   4. 1854

      > Zenith-distances and azimuths form..a system of angles, by means of which it is easy to fix the positions of the stars with extreme precision.

      L. Tomlinson, translation of D. F. J. Arago, Popular Lectures on Astronomy 41
   5. 1934

      > Corrections for refraction must be applied to all astronomical observations in order to reduce apparent zenith distance to true zenith distance.

      H. S. Jones, General Astronomy (ed. 2) ii. 26
   6. 2009

      > At large zenith distances, each point-like stellar image is widened to a noticeable spectrum.

      H. W. Duerbeck in G. D. Roth, Handbook Pract. Astronomy viii. 210
   astronomy
   1. declination c1400–
      Astronomy. The angular distance of a heavenly body (north or south) from the celestial equator, measured on a meridian passing through the body…
   2. meridian altitude c1400–
      The altitude of the sun at noon, or of any celestial object as it crosses the meridian.
   3. angle of position?a1560–
      The angle between the direction of a point and some other direction regarded as fundamental; spec. (a) the angle formed at the eye by the lines of…
   4. amplitude 1585–
      Astronomy. The direction of a celestial object from an observer, expressed as the angular distance from the east or west point on the horizon to the…
   5. zenith distance 1588–
      The angular distance of a celestial object from the zenith (the complement of its altitude or angular distance from the horizon).
   6. refraction 1603–
      Astronomy. The effect of the atmosphere whereby light from a celestial object far from the zenith is deflected so as to increase the apparent…
   7. azimuth 1626–
      The angular distance of any such circle from a given limit, e.g. a meridian. Hence, the true azimuth of a heavenly body is, the arc of the horizon…
   8. horizontal parallax 1665
      Of or belonging to the horizon; situated on or occurring at the horizon. Now chiefly in special collocations, as horizontal parallax, the…
   9. complement 1703–
      Astronomy. The difference between the altitude, latitude, declination, etc. of a heavenly body, and 90 degrees. Abbreviated coaltitude, n., co-lat…
   10. aberration 1737–
       Astronomy. An apparent displacement of a celestial object from its true position, arising from the combined effect of the observer's motion and the…
   11. hour-angle 1837–
       The angular distance between the meridian and the declination-circle passing through a heavenly body, which is the measure of the sidereal time…
   12. intercept 1901–
       Navigation. The angular difference between the calculated and the observed zenith distances of a heavenly body.
   View in Historical Thesaurus

## Frequency

zenith distance typically occurs about 0.07 times per million words in modern written English.

zenith distance 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 zenith distance, n., 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 | 0.29
1760 | 0.3
1770 | 0.29
1780 | 0.32
1790 | 0.48
1800 | 0.43
1810 | 0.48
1820 | 0.51
1830 | 0.51
1840 | 0.53
1850 | 0.51
1860 | 0.4
1870 | 0.35
1880 | 0.33
1890 | 0.31
1900 | 0.29
1910 | 0.27
1920 | 0.25
1930 | 0.22
1940 | 0.2
1950 | 0.17
1960 | 0.14
1970 | 0.12
1980 | 0.089
1990 | 0.071
2000 | 0.047
2010 | 0.036

Originally published as part of the entry for zenith, n. & adj.

zenith, n. & adj. was revised in June 2018.