Roam around after a smell (5)
I believe the answer is:
aroma
'smell' is the definition.
(synonyms)
'roam around after a' is the wordplay.
'around' indicates anagramming the letters.
'after' is a charade indicator (letters next to each other).
'roam' with letters rearranged gives 'arom'.
'arom'+'a'='AROMA'
(Other definitions for aroma that I've seen before include "Food fragrance" , "Pervasive quality" , "Savour" , "Spicy fragrance" , "A pleasant smell as of food" .)