The most common and most likely answer to this crossword clue is the 7 letter word PAIRING
I've seen this crossword clue in Independent
P
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Buddy explains!
The straight part
We know that "Parliamentary convention" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case parliamentary convention = pairing.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 PAIRING mean?
PAIRING verb- To group into one or more sets of two.
- To bring two (animals, notably dogs) together for mating.
- To engage (oneself) with another of opposite opinions not to vote on a particular question or class of questions.
- To suit; to fit, as a counterpart.
- To impair, to make worse.
- To become worse, to deteriorate.
- The combination or union of two things.
- An agreement between two members of a legislative body holding opposite opinions to refrain from voting, so that both may absent themselves.