Quid
wiktionary
Borrowed from Latin quid(“what, something”), neuter singular of quis(“who”).
Likely derives from the phrase quid pro quo(“this for that”), referring to the exchange of goods/services for money.
From Middle English quide, quede, from Old English cwidu, cwudu(“that which is chewed, cud”). Doublet of cud.
etymonline
quid (n.1)
"bite-sized piece" (of tobacco, etc.), "a portion suitable to be chewed or held in the mouth," 1727, dialectal variant of Middle English cudde, from Old English cudu, cwidu (see cud).
quid (n.2)
"a sovereign, one pound sterling," 1680s, British slang, possibly from quid "that which is, essence," (c. 1600, see quiddity), as used in quid pro quo (q.v.), or directly from Latin quid "what, something, anything." Compare French quibus, noted in Barrêre's dictionary of French argot (1889) as a word for "money, cash," said to be short for quibus fiunt omnia (see quibble (n.)).
