Better finish for limping walker (7)
I believe the answer is:
gambler
'better' is the definition.
(a gambler is someone who bets)
'finish for limping walker' is the wordplay.
'finish for' indicates one should take the final letters (the letter which finishes the word).
'walker' becomes 'ambler' (I've seen this before).
The last letter of 'limping' is 'g'.
'g'+'ambler'='GAMBLER'
(Other definitions for gambler that I've seen before include "One who takes risks" , "Better" , "Casino punter" , "One who bets" , "Risk taker" .)