Sweet smell – and something annoying (6)
I believe the answer is:
humbug
'sweet' is the definition.
(boiled sweet)
'smell and something annoying' is the wordplay.
I cannot quite see how this works, but
'smell' could be 'hum' (something with a bad smell is 'humming') and 'hum' is found within the answer.
The remaining letters 'bug' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for humbug that I've seen before include "Dickensian kind of hypocrite" , "Trick; rubbish" , "Minty sweet" , "Pretentious talk or boiled sweet" , "Baloney" .)