Australian hip slang for coffee.

A casual invitation / threat used by an individual that is not afraid of fucking someone up.

In old Scots the word "coff" meant to buy, purchase, or barter (Scottish Dictionary by John Jamieson 1840)
Coff is still used in some parts of the North East of Scotland most predominantly in Dingwall and Muir-of-Ord (The Muir) usually following "gudgie" (a short stout fellow J. Jamieson, 1840) but today refers to any type of man "gudgie-coff" or just "coff"
The historical use of gudgie-coff may have referred to a fatman who was buying or purchasing something in the market towns of Dingwall and Muir of Ord but this is unproven. Nevertheless, there are certainly plenty fatmen purchasing things still today in Dingwall at the local Tesco.

A sly way to tell someone, fuck off. Normally used by pupils towards their teachers, or by any one towards a person of authority. Sometime followed by a pretend cough (the more sarcastic the better).

Lazy/discrete/suttle way of saying FUCKOFF
The repulsive excuse for a human who is speaking to you does not even deserve to be insulted in a way that utilizes your full energy. Simply coff them. You may also cough them aswell cough cough.