Recoiling at street drug sample (5)
I believe the answer is:
taste
'sample' is the definition.
(I know that sample can be written as taste)
'recoiling at street drug' is the wordplay.
'recoiling' is a reversal indicator.
'street' becomes 'st' (abbreviation).
'drug' becomes 'e' (E is another name for ecstasy).
'at' back-to-front is 'ta'.
'ta'+'st'+'e'='TASTE'
(Other definitions for taste that I've seen before include "Experience - discrimination" , "A test (anag)" , "Sample orally" , "Sample by eating or drinking a little" , "To eat sparingly" .)