The most common and most likely answer to this crossword clue is the 7 letter word POLEMIC
I've seen this crossword clue in The Guardian
P
O
L
E
M
I
C
More clues leading to the result POLEMIC
- Controversial elements of boom in filming?
- Argument from European male in charge
- Disputatious European means to be heard
- European means to be heard in argument
- Controversial European music putting US off
- Attack tools for singing stripper?
- Controversial Eastern European recording device
- Controversial photo captures expression of victory by metres
- Uneasily compile controversial writing
- Fixing particular transducer to mast brings about dispute
Buddy explains!

The straight part
We know that "argument" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case argument = polemic.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 POLEMIC mean?
POLEMIC noun- A person who writes in support of one opinion, doctrine, or system, in opposition to another; one skilled in polemics; a controversialist; a disputant.
- An argument or controversy.
- A strong verbal or written attack on someone or something.
- Having the characteristics of a polemic.