The most common and most likely answer to this crossword clue is the 6 letter word CONGAS
I've seen this crossword clue in The Guardian
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More clues leading to the result CONGAS
Buddy explains!
The straight part
We know that "party lines" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case party lines = congas.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 CONGAS mean?
CONGAS noun- A tall, narrow, single-headed Cuban hand drum of African origin
- A march of Cuban origin in four-four time in which people form a chain, each holding the hips of the person in front of them; in each bar, dancers take three shuffle steps and then kick alternate legs outwards at the beat; the chain weaves around the place and allows new participants to join the back of the chain
- To dance the conga.