The most common and most likely answer to this crossword clue is the 8 plus 7 letter word SPARRING PARTNER
I've seen this crossword clue in The Daily Telegraph
S
P
A
R
R
I
N
G
P
A
R
T
N
E
R
More clues leading to the result SPARRING PARTNER
- King collared by parsimonious consort with whom words are often exchanged
- Call after argument with associate of training provider
- Friend mean to protect right with standard rent rising
- Mate being miserly — about right, with average rise of lease
- Pole’s band put by standard retrospective fee for disputatious associate
- Spouse during a disagreement?
- Careful to include king, his consort, and friend to argue with?
Buddy explains!
The straight part
We know that "friend to argue with" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case friend to argue with = sparring partner.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.