Tedious job in the Smoke (3)

I believe the answer is:

fag

I'm a little stuck... Click here to teach me more about this clue!

'the smoke' is the definition.
(both can mean a cigarette)

I can't explain the remainder of the clue.

(Other definitions for fag that I've seen before include "Hard work - cigarette (slang)" , "Ciggie" , "an awful bore!" , "Cigarette for a menial schoolboy" , "smoke" .)

I've seen this clue in The Times.

Want a hint initially instead of a full solution? Install my app