The most common and most likely answer to this crossword clue is the 2 plus 1 plus 3 letter word IN A ROW
I've seen this crossword clue in Financial Times
I
N
A
R
O
W
More clues leading to the result IN A ROW
- One after the other having an argument
- Running without queen’s backing
- … continuously having an argument
- Consecutively arguing?
- One after the other having an altercation
- Like all the pretty maids, fighting
- Where eight might be found as an unbroken sequence
- When voices may be raised sequentially
- Independent, conservative having left-right aligned
- One after the other forming a line
Buddy explains!

The straight part
We know that "Consecutively/arguing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case consecutively/arguing = in a row.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.