Person desperate for a fag? (6)
I believe the answer is:
gasper
'a fag?' is the definition.
(slang term for a cigarette)
'person desperate' is the wordplay.
I cannot quite understand how this works, but
'person' could be 'per' (abbreviation) and 'per' is found within the answer.
The remaining letters 'gas' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'for' is the link.
Can you help me to learn more?
(Other definitions for gasper that I've seen before include "Grapes (anag) -- cigarette (slang)" , "Ciggie" , "Pagers (anag) - cigarette (slang)" , "fag" , "One puffing" .)