Do you know ghouls from goblins and ghosts?
late 14c., "to gallop," possibly from Old North French *waloper (13c.), probably from Frankish *walalaupan "to run well" (cf. Old High German wela "well" and Old Low Franconian loupon "to run, leap"). The meaning "to thrash" (1820) and the noun meaning "heavy blow" (1823) may be separate developments, of imitative origin. Related: Walloped; walloping.
[1823+; fr British dialect, ''beat, thrash,'' apparently fr Old Norman French walop, ''gallop'']
Extreme; large: walloping amount of chili