Omit a car - terribly smelly (8)
I believe the answer is:
aromatic
'smelly' is the definition.
(I've seen this before)
'omit a car terribly' is the wordplay.
'terribly' indicates an anagram.
'omit'+'a'+'car'='omitacar'
'omitacar' with letters rearranged gives 'AROMATIC'.
(Other definitions for aromatic that I've seen before include "With a strong pleasant smell" , "Fragrant or spicy, smells nice" , "Having fragrance (of herb)" , "Pleasant sort of smell from Cairo mat" , "herb, perhaps" .)