Bad breath (9)
I believe the answer is:
halitosis
'bad breath' is the definition.
(I know that bad breath can be written as halitosis)
This is all the clue.
(Other definitions for halitosis that I've seen before include "repulsive pants?" , "Bad breath, smells unpleasant" , "Smelly breath" , "offensive condition" , "Foul breath problem" .)