Charybdis, Maelstrom, back stream, backflow, backwash, backwater, centrifugate, centrifuge, countercurrent, counterflow, counterflux, dizzy round, eddy, gulf, gyre, maelstrom, pirouette, purl, rat race, reel, refluence, reflux, regurgitation, round, spin, surge, swirl, turn, twirl, vortex, wheel, whirl, whirligig, whirlpool, whirlwind, whorl