Deserter

(n.) One who forsakes a duty, a cause or a party, a friend, or any one to whom he owes service; especially, a soldier or a seaman who abandons the service without leave; one guilty of desertion.

Thesaurus Entries

Sabbath-breaker, absconder, apostasy, apostate, atheist, backslider, betrayal, blasphemer, bolt, bolter, breakaway, collaborationist, collaborator, convert, defection, defector, dereliction, desertion, escapee, fifth columnist, fugitive, mugwump, outlaw, proselyte, quisling, rat, ratting, recidivist, recreant, renegade, renegado, renegate, reversionist, runagate, runaway, sacrilegist, schism, schismatic, seceder, secession, secessionist, separatist, strikebreaker, tergiversant, tergiversator, traitor, turnabout, turncoat, turntail, unbeliever, walkout