Try a test, perhaps (5)
I believe the answer is:
taste
'try' is the definition.
('taste' can be a synonym of 'try')
'a test perhaps' is the wordplay.
'perhaps' indicates anagramming the letters.
'a'+'test'='atest'
'atest' is an anagram of 'TASTE'.
(Other definitions for taste that I've seen before include "Liking (for)" , "eat only the smallest amount" , "Savour; discernment" , "Gustatory sensation" , "Savour, relish" .)