Grouse is good and ready to eat (5)
I believe the answer is:
gripe
'grouse' is the definition.
(I know that grouse can be written as gripe)
'good and ready to eat' is the wordplay.
'good' becomes 'g' (abbreviation).
'and' is a charade indicator (letters next to each other).
'ready to eat' becomes 'ripe' (I've seen this before).
'g'+'ripe'='GRIPE'
'is' acts as a link.
(Other definitions for gripe that I've seen before include "Trivial complaint" , "Complain; colic (water)" , "Complain; stomach pain" , "Protest" , "carp" .)