Meaning

noun (often followed by `of') a large number or amount or extent

verb turn sharply; change direction abruptly

verb move obliquely or sideways, usually in an uncontrolled manner

originAblaut of slay, from Middle English slew, sleugh, past of Middle English sleen. Replaced earlier Middle English slough, slogh, from Old English slōg (past of Old English slēan (“to hit, strike, slay”)), due to the influence of knew, drew, etc. More at slay.

Etymology from Wiktionary, CC BY-SA 3.0