Odd cut to backside (3)
I believe the answer is:
'odd' is the definition.
'cut to backside' is the wordplay.
'cut' means to remove the last letter.
'to backside' becomes 'rump' ('rump' can be a synonym of 'backside').
'rump' with its last letter removed is 'RUM'.
(Other definitions for rum that I've seen before include "Strange; spirit" , "Queer" , "Odd spirit from sugar cane" , "Unusual" , "Droll" .)