The most common and most likely answer to this crossword clue is the 12 letter word COORDINATION
C
O
O
R
D
I
N
A
T
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The straight part
We know that "Working together" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case working together = coordination.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 COORDINATION mean?
COORDINATION noun- The act of coordinating, making different people or things work together for a goal or effect.
- The resulting state of working together; cooperation; synchronization.
- The ability to coordinate one's senses and physical movements in order to act skillfully.
- (possibly archaic) the state of being equal in rank or power.
- (grammar) An equal joining together of two or more phrases or clauses, for example, using and, or, or but.
- The reaction of one or more ligands with a metal ion to form a coordination compound.