Synonyms of flail in English:

flail


See definition of flail

verb

1‘he fell headlong, his arms flailing’

SYNONYMS
wave, swing, thrash about, flap about, beat about, windmill, move erratically

2‘I was flailing about in the water’

SYNONYMS
flounder, struggle, thrash, thresh, squirm, wriggle, writhe, twist, splash, stumble, blunder, fumble, wiggle, twitch

3‘he flailed their shoulders with his cane’

SYNONYMS
thrash, beat, strike, batter, drub, flog, whip, lash, scourge, flay, flagellate, strap, switch, tan, cane, tan someone's hide, whip someone's hide, give someone a hiding, beat the living daylights out of, clout, welt, belabour
informal wallop, whack, lam, give someone a hiding, give someone a good hiding, larrup