A lot vs. Alot: 9 Grammatical Pitfalls
early 15c., "whirlpool, eddy," originally Scottish, perhaps related to dialectal Norwegian svirla or Dutch zwirrelen "to whirl." The meaning "whirling movement" is from 1818.
1510s, with an isolated instance from 14c.; from swirl (n.). Related: Swirled; swirling.