Smells awful (5)
I believe the answer is:
reeks
'smells awful' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for reeks that I've seen before include "offensive odours" , "Smells very strongly" , "Gives off a strong unpleasant smell" , "Macgillycuddy's - -" , "Is humming" .)