Sounds like karma is fair (4)
I believe the answer is:
fete
'fair' is the definition.
(I've seen this before)
'sounds like karma' is the wordplay.
'sounds like' indicates a 'sounds like' (homophone) clue.
'karma' becomes 'fate' (I've seen this in another clue).
'fate' is a homophone of 'FETE'.
'is' acts as a link.
(Other definitions for fete that I've seen before include "Outdoor fundraiser" , "Garden event" , "Charity garden party" , "A festival of feet" , "Outdoor get-together" .)