Scent a wanderer picked up (5)
I believe the answer is:
aroma
'scent' is the definition.
(synonyms)
'a wanderer picked up' is the wordplay.
'wanderer' becomes 'roamer' (someone roaming around).
'picked up' shows a homophone (sound like).
'roamer' sounds like 'roma'.
'a'+'roma'='AROMA'
(Other definitions for aroma that I've seen before include "Pervasive quality" , "Perfume" , "Stink" , "Distinctive odour" , "A pleasant smell as of food" .)