Meaning : Someone who assists in a plot.
Synonyms : confederate, henchman, partner in crime
Meaning : Someone who collaborates with an enemy occupying force.
Synonyms : collaborationist, quisling
Meaning : An associate in an activity or endeavor or sphere of common interest.
Example :
The musician and the librettist were collaborators.
Sexual partners.
Synonyms : cooperator, pardner, partner