quid

The inherent nature of something.

A member of a section of the Democratic-Republican Party between 1805 and 1811, following John Randolph of Roanoke. (From tertium quid.)

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?

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.

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.

Pound sterling. (usually only used with a whole number of pounds)

Seven quid for a toastie? Are you taking the mick?!

Forty quid a fuckin ticket. No shy they British Rail cunts, ah kin fuckin tell ye.

Various national currencies typically known by the name "pound".

Euro.

Dollar, dollars.

A piece of material for chewing, especially chewing tobacco.

Then he lay quiet for a little, and then, pulling out a stick of tobacco, begged me to cut him a quid.

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, […]

The act of chewing such tobacco.