Collaborator

Etymology
From collaborateur.

Noun

 * 1) a person who collaborates

Thesaurus
Trojan horse, advertising writer, annalist, apostate, art critic, author, authoress, backslider, belletrist, bibliographer, bolter, coauthor, collaborationist, columnist, compiler, composer, convert, copywriter, creative writer, critic, crypto, dance critic, defector, deserter, diarist, drama critic, dramatist, encyclopedist, essayist, fellow traveler, fifth column, fifth columnist, fraternizer, free lance, free-lance writer, ghost, ghostwriter, humorist, inditer, literary artist, literary craftsman, literary critic, literary man, litterateur, logographer, magazine writer, man of letters, monographer, mugwump, music critic, newspaperman, novelettist, novelist, pamphleteer, penwoman, poet, prose writer, proselyte, quisling, recidivist, recreant, renegade, renegado, renegate, reversionist, reviewer, runagate, saboteur, scenario writer, scenarist, schismatic, scribe, scriptwriter, seceder, secessionist, security risk, separatist, short-story writer, storyteller, strikebreaker, subversive, technical writer, tergiversant, tergiversator, traitor, turnabout, turncoat, turntail, underground, word painter, wordsmith, writer