1560s, "to fight, struggle, contend" (intransitive), from French combat (16c.), from Old French combattre (12c.), from Late Latin combattere, from Latin com "with (each other)," see com-, + battuere "to beat, fight" (see batter (v.)). Transitive sense is from 1580s; figurative sense from 1620s. Related: Combated; combating; combatted; combatting.
1560s, "a fight," originally especially "a fight between two armed persons" (later distinguished as single combat, 1620s), also in a general sense of "any struggle or fight between opposing forces," from French combat (see combat (v.)).