(n) an associate in an activity or endeavor or sphere of common interest, Syn. cooperator, pardner, partner, Example:the musician and the librettist were collaborators; sexual partners
The Collaborative International Dictionary of English (GCIDE) v.0.53 Collaborative International Dictionary (GCIDE)
n. [ L. collaborare to labor together; col- + laborare to labor: cf. F. collaborateur. ] 1. An associate in labor, especially in literary or scientific labor. [ 1913 Webster ]
2. one who willingly cooperates with an enemy, especially an enemy nation occupying one's own country. [ PJC ]