zwitterionic, adj.

zwitterionic
http://www.oed.com/dictionary/zwitterionic_adj%3Ftab%3Dmeaning_and_use
First published 1986; not fully revised

# zwitterionicadjective

## Factsheet

### What does the adjective zwitterionic mean?

There is one meaning in OED's entry for the adjective zwitterionic. 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 adjective zwitterionic?

About 0.06occurrences per million words in modern written English

1940 | 0.015
1950 | 0.025
1960 | 0.034
1970 | 0.04
1980 | 0.051
1990 | 0.058
2000 | 0.068
2010 | 0.075

### Where does the adjective zwitterionic come from?

Earliest known use

1940s

The earliest known use of the adjective zwitterionic is in the 1940s.

OED's earliest evidence for zwitterionic is from 1946, in Nature: a weekly journal of science.

### Nearby entries

1. zuz, n. 1688–
2. zwanziger, n. 1828–
3. Zweig, n. 1973–
4. zwieback, n. 1894–
5. zwieselite, n. 1861–
6. Zwinglian, n. & adj. 1532–
7. Zwinglianism, n. 1581–
8. Zwinglianist, n. 1673–1759
9. zwischenzug, n. 1941–
10. zwitterion, n. 1906–
11. zwitterionic, adj.1946–
12. Zydeco, n. 1949–
13. zygadite, n. 1861–
14. zygaena, n. 1717–
15. zygaenid, n. & adj. 1913–
16. zygaenidan, n. 1837–
17. zygal, adj. 1886–
18. zygantrum, n. 1854–
19. zygapophysial, adj. 1870–
20. zygapophysis, n. 1854–
21. zygite, n. 1888–

## Meaning & use

Chemistry.

1. 1946–
   See zwitterion n.
   Stressed as ˌzwitteriˈonic.
   1. 1946

      > A hybrid structure derived from a number of ionic states of which there are..eight zwitterionic forms.

      Nature 16 November 703/1
   2. 1949

      > These [substances]..may be neutral, acidic, basic, or zwitterionic.

      E. P. Abraham & N. G. Heatley in H. W. Florey et al., Antibiotics vol. I. ii. 94
   3. 1981

      > Vesicles of zwitterionic phosphatidylcholine.

      Biochimica et Biophysica Acta vol. 668 117
   chemistry
   1. zwitterionic 1946–
   View in Historical Thesaurus

## Frequency

zwitterionic typically occurs about 0.06 times per million words in modern written English.

zwitterionic 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 zwitterionic, adj., 1940–2010

* 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
--- | ---
1940 | 0.015
1950 | 0.025
1960 | 0.034
1970 | 0.04
1980 | 0.051
1990 | 0.058
2000 | 0.068
2010 | 0.075

### Frequency of zwitterionic, 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.

Period | Frequency per million words
--- | ---
2017 | 0.0028
2018 | 0.0054
2019 | 0.0093
2020 | 0.012
2021 | 0.019
2022 | 0.024
2023 | 0.027
2024 | 0.028

Originally published as part of the entry for zwitterion, n.

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