also fag-end
( fag ends)
1.
A fag end is the last part of a cigarette, which people throw away when they have smoked the rest. ( BRIT INFORMAL )
= butt
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2.
If you refer to the fag end of something, you mean the last part of it, especially when you consider this part boring or unimportant. ( INFORMAL )
He never had much confidence in his judgement at the fag-end of the working day.
N-COUNT : usu sing , N of n