Sinned a little, altogether redeemable (5)
I believe the answer is:
erred
'sinned' is the definition.
(I've seen this before)
'a little altogether redeemable' is the wordplay.
'a little' indicates a hidden word.
'ERRED' is hidden within 'altogether redeemable'.
(Other definitions for erred that I've seen before include "Made mistake, was incorrect" , "Committed a sin" , "Gone astray!" , "Went wrong" , "Made a mistake, was wrong" .)