quid

Etymology 1

Borrowed from Latin quid (“what, something”), neuter singular of quis (“who”).

noun

1. The inherent nature of something.
2. (US, historical) A member of a section of the Democratic-Republican Party between 1805 and 1811, following John Randolph of Roanoke. (From tertium quid.)
3. Paired with quo, in reference to the phrase quid pro quo (“this for that”): something offered in exchange for something else.
   […]; but what is the quo for which they ought to give the quid? you say they ought to give a quid pro quo; what is the quo? […]; did not they give you a pretty handsome quid for the quo there? 19 May 1886, Report from the Select Committee of the House of Lords on the Electric Lighting Act (1882) Amendment (No. 1) Bill [H.L.]; the Electric Lighting Act (1882) Amendment (No. 2) Bill [H.L.]; Together with the Proceedings of the Committee, Minutes of Evidence, and Appendix, London: […]Henry Hansard and Son, page 208
   Indeed, asymmetry precludes the possibility of pointing to any particular quo that is meant to recompense the quid. […]If there exists any kind of inequity between quid and quo, then—on this line of argument—the expansive category of “friendship” emerges to account for it, siphoning the situation away from the class of objectionable quid pro quo. The claim officials here make—that for a quid to have a quo there must be some equivalency between the two—draws theoretical sustenance from the objective, exclusionary approach that critics of classical contract law apply to disproportionate exchanges. 2000, Andrew Stark, Conflict of Interest in American Public Life, pages 163–164
   Corruption, the Court declared in Buckley v. Valeo, involves a quid pro quo: an officeholder doing something in office in return for money or some other favor provided by another individual or entity (for our purposes, a corporation). The problem, however, is that in principle there can be a quid—the money or favor offered by the business to the official—and a quo—the action taken by the official that benefits the business—without any clear evidence of a pro, that is, that the two are connected.[…]The “pro,” the connection between quid and quo, might take place only inside the minds of the official and businessperson concerned. 2009, George G. Brenkert, Tom L. Beaucham, editors, The Oxford Handbook of Business Ethics, Oxford University Press, page 504
   It is hard to pull off a quid pro quo if the holder of the quo doesn’t know about the quid. 2020, John Yoo, Defender in Chief: Donald Trump’s Fight for Presidential Power, New York, N.Y.: All Points Books, St. Martin’s Publishing Group

Etymology 2

Likely derives from the phrase quid pro quo (“this for that”), referring to the exchange of goods/services for money.

noun

1. (historical) A sovereign or guinea, that is, a certain coin or amount of money.
   They invited him to come to-morrow, […] and bring half a quid with him. 1870, Charles Reade, Put Yourself in His Place
2. (Britain, colloquial) Pound sterling. (usually only used with a whole number of pounds)
   Seven quid for a toastie? You're joking aren't you?!
3. (Ireland, Australia, New Zealand, colloquial, historical) Various national currencies typically known by the name "pound".
4. (Ireland, colloquial, by extension) Euro.
5. (Australia, New Zealand, colloquial, by extension, rare) Dollar, dollars.

Etymology 3

From Middle English quide, quede, from Old English cwidu, cwudu (“that which is chewed, cud”). Doublet of cud.

noun

1. A piece of material for chewing, especially chewing tobacco.
   He broke off to open a small brass tobacco-box and place a little quid of tobacco tenderly into a pouch in his left cheek, […] 1901, W. W. Jacobs, chapter 1, in Light Freights, page 1
2. (US, colloquial) The act of chewing such tobacco.

verb

1. To chew tobacco.
   Ah! the pig-tailed, quidding pirates and the pretty pranks we played 1902, John Masefield, A Ballad of John Silver
2. (of a horse) To let food drop from the mouth whilst chewing.