Letter following complaint? (4)
I believe the answer is:
beef
'complaint?' is the definition.
(I've seen this before)
'letter following' is the wordplay.
'letter' becomes 'bee' (the letter B).
'following' becomes 'f.' (used when citing page numbers etc).
'bee'+'f'='BEEF'
(Other definitions for beef that I've seen before include "Complaint; strength" , "joint, perhaps" , "it's unacceptable for vegetarian" , "Meat of the cow" , "Grouse - meat" .)