SYN: Assistant, ally, cooperator, accessory, accomplice.
ANT: Opponent, counteractor, antagonist, baffler, adversary.
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KEY: Coalesce.
SYN: Harmonize, blend, mix, combine, join, unite, amalgamate, cohere.
ANT: Disagree, discomport.
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KEY: Coalition.
SYN: Combination, consentaneity, compromise, consociation, union, alliance, league, compact, amalgamation, composition, confederacy.
ANT: Dissociation, disruption, disagreement, dissentience.