The most common and most likely answer to this crossword clue is the 9 letter word COOPERATE
I've seen this crossword clue in The Guardian
C
O
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P
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More clues leading to the result COOPERATE
- Help when old boxer downed
- Work with barrel-maker, brewing tea
- Join in as craftsman took a meal
- Bill’s partner and childless individual had to pull together
- Help senior officer to function
- Our Henry put away work altogether, so I’ve heard
- Pull together to manage without old level of payment
- Be willing to assist barrel maker, worried
- Entertainment in bed — stroke bottom, then pull together
- Old comedian scoffed to do what the two Ronnies did
Buddy explains!
The straight part
We know that "Join in" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case join in = cooperate.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 COOPERATE mean?
COOPERATE verb- To work or act together, especially for a common purpose or benefit.
- To allow for mutual unobstructed action
- To function in harmony, side by side
- To engage in economic cooperation.