The most common and most likely answer to this crossword clue is the 8 letter word COMPLAIN
I've seen this crossword clue in The Times
C
O
M
P
L
A
I
N
More clues leading to the result COMPLAIN
- Arrive shortly on flat territory and grumble
- Fellow politician in US city first to gripe
- Clubs order unseasoned beef
- Firm initially monitors scheme to import island's beef
- Sleep cut short, leading to obvious bellyache
- Change around a switch in lamp to see rail or grouse?
- Bellyache is condition that’s not terminal
- Beef of new policeman drained of energy
- Grumble when evening service is cut short, penning article
- Carp caught by old member — Frank
Buddy explains!

The straight part
We know that "beef" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case beef = complain.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does COMPLAIN mean?
COMPLAIN verb- To express feelings of pain, dissatisfaction, or resentment.
- To make a formal accusation or bring a formal charge.
- To creak or squeak, as a timber or wheel.