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.)).
mid-15c. (adj.) "contending, disposed to combat;" late 15c. (n.) "one who engages in battle;" from Old French combatant (Modern French combattant) "skilled at fighting, warlike" (also used as a noun in Old French), present-participle adjective of combattre (see combat (v.)).
late 15c., duelle (from late 13c. in Latin form), "a single combat," also "a judicial single combat," from Medieval Latin duellum "combat between two persons," from Latin duellum "war," an Old Latin form of bellum (see bellicose). The Old Latin word was retained in poetic and archaic language and apparently given a special meaning in Medieval or Late Latin of "one-on-one combat" on fancied connection with duo "two."
Sometimes also in Italian form duello. The English word by 1610s had taken on the specialized sense of "premeditated and pre-arranged single combat involving deadly weapons in the presence of at least two witnesses." General sense of "any contest between two parties" is from 1590s.
"engage in single combat, fight a duel," 1640s, see duel (n.). Related: Dueled; dueling; duelling.
in reference to combat or competition, "hand to hand," 1970s, Spanish, from mano "hand," from Latin manus "hand" (from PIE root *man- (2) "hand").