俚语，来自quid, pro quo,一物换一物。
- quid: English has two words quid. The colloquial term for a ‘pound’ appears to be the same word as Latin quid ‘something’, and may have been inspired by the expression quid pro quo , literally ‘something for something’. Quid ‘piece of chewing tobacco’  is a variant of cud.
- quid (n.1)
- "bite-sized piece" (of tobacco, etc.), 1727, dialectal variant of Middle English cudde, from Old English cudu, cwidu (see cud).
- quid (n.2)
- "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) for "money, cash," said to be short for quibus fiunt omnia.
- 1. I'll pay you back that two quid tomorrow.
- 2. It cost him five hundred quid.
- 3. Can you lend me five quid?
- 4. He earns at least 300 quid a week.
- 5. They share a great deal of information on a quid pro quo basis.
[ quid 造句 ]