Quid has various meanings:

• The Latin word for "what"; in a deeper sense it refers to the core meaning of something.
• British slang for one pound sterling (£), originally referring to the pound note (plural is quid, not quids, despite the expression "quids in", referring to a financially positive end to a transaction or venture). The Irish pound and the Australian pound were also referred to by this name. The term is also used for the Euro in Ireland, although the term "yo-yo" has also been coined for this.
• A French thematic encyclopaedia, published annually by Robert Laffont.
• An abbreviation of the Latin "tertium quid", meaning "third party" and used to denote an anti-Madison part of the Democratic-Republican Party of the United States between 1805 and 1811.
• A piece of tobacco, small enough to be chewed.

Quid