Brawl
late Middle English: perhaps ultimately imitative and related to bray1.
wiktionary
The verb is derived from Late Middle English braulen, brall, brallen(“to clamour, to shout; to quarrel; to boast”); [1] further etymology is uncertain, but the word could be related to bray and ultimately imitative. [2] It may be cognate with Danish bralle(“to chatter, jabber”), Dutch brallen(“to boast”), Low German brallen(“to brag”), Middle High German prālen(“to boast, flaunt”) (modern German prahlen(“to boast, flaunt, vaunt”)). [3]
The noun is derived from Middle English brall, bralle, braul, braule, brawle(“disturbance, squabble; brawl”), from the verb braulen: see above. [4]
Possibly from French branler(“to shake”), [5] from Old French brandeler(“to shake, wave; to agitate”), from brand, branc(“blade of a sword”), from Vulgar Latin *brandus(“firebrand; flaming sword; sword”), ultimately from Proto-Indo-European *bʰrenu-(“to burn”).
From French branle(“type of dance; an act of shaking, a shake”), from branler(“to shake”), from Old French brandeler(“to shake, wave; to agitate”); [6]see further at etymology 2.
Alternatively, the word could be derived from brawl(“(obsolete) to move to and fro, quiver, shake”): see etymology 2. [6]
etymonline
brawl (v.)
late 14c., braulen "to cry out, scold, quarrel," probably related to Dutch brallen "to boast," or from French brailler "to shout noisily," frequentative of braire "to bray" (see bray (v.)). Meaning "quarrel, wrangle, squabble" is from early 15c. Related: Brawled; brawler; brawling.
brawl (n.)
mid-15c., "noisy disturbance," from brawl (v.). Meaning "fist-fight" is by 1873.