Battle
Middle English: from Old French bataille (noun), bataillier (verb), based on late Latin battualia ‘military or gladiatorial exercises’, from Latin battuere ‘to beat’.
wiktionary
From Middle English batel, batell, batelle, batayle, bataylle, borrowed from Old French bataille, from Late Latin battālia, variant of battuālia(“fighting and fencing exercises”) from Latin battuō(“to strike, hit, beat, fight”), from a Gaulish root from Proto-Indo-European *bʰedʰ-(“to stab, dig”). Doublet of battalia and battel.
Displaced native Old English ġefeoht.
From Early Modern English batell, probably from Middle English *batel(“flourishing”), from Old English *batol(“improving, tending to be good”), from batian(“to get better, improve”) + -ol ( + -le).
etymonline
battle (n.)
"fight or hostile engagement between opposing forces," c. 1300, from Old French bataille "battle, single combat," also "inner turmoil, harsh circumstances; army, body of soldiers," from Late Latin battualia "exercise of soldiers and gladiators in fighting and fencing," from Latin battuere "to beat, to strike" (see batter (v.)).
Battle-cry is from 1812; battle-flagfrom 1840; battle-scarred is from 1848. Phrase battle royal "fight involving several combatants" is from 1670s.
battle (v.)
early 14c., "to fight," from French batailler (12c.), from bataille (see battle (n.)). Related: Battled; battling.