Insect following grouse (4)
I believe the answer is:
beef
'grouse' is the definition.
('beef' can be a synonym of 'grouse')
'insect following' is the wordplay.
'insect' becomes 'bee' (bee is a kind of insect).
'following' becomes 'f' (used when citing page numbers etc).
'bee'+'f'='BEEF'
(Other definitions for beef that I've seen before include "Brawn; grumble" , "Grumble over cattle meat?" , "Bovine flesh" , "Brawn; complaint" , "Type of meat" .)