Medical procedure possibly reduced lameness on reflection (5)
I believe the answer is:
enema
'medical procedure' is the definition.
(I've seen this before)
'reduced lameness on reflection' is the wordplay.
'reduced' says the answer is hidden in the clue (reducing the letters in the clue shows the answer).
'on reflection' shows that the letters should be reversed in order.
'amene' is hidden within 'lameness'.
'amene' back-to-front is 'ENEMA'.
'possibly' is the link.
(Other definitions for enema that I've seen before include "treatment by rear entrance" , "Liquid injection given as a laxative" , "In the end medical procedure" , "Suppository" , "Stern action from nurse perhaps" .)