"to cook," late 14c. (earlier "to burn," mid-14c.), from Old French bruller "to broil, roast" (Modern French brûler), earlier brusler "to burn" (11c.), which, with Italian bruciare, is of uncertain and much-disputed origin.
Perhaps from Vulgar Latin *brodum "broth," borrowed from Germanic and ultimately related to brew (v.). Gamillscheg proposes it to be from Latin ustulare "to scorch, singe" (from ustus, past participle of urere "to burn") and altered by influence of Germanic "burn" words beginning in br-. Related: Broiled; broiling.