Old English spreawlian "move convulsively," with cognates in the Scandinavian languages (such as Norwegian sprala, Danish sprælle) and North Frisian spraweli, probably ultimately from PIE root *sper- (4) "to strew" (see sprout (v.)). Meaning "to spread out" is from c. 1300. That of "to spread or stretch in a careless manner" is attested from 1540s; of things, from 1745. Related: Sprawled; sprawling.
1719, from sprawl (v.); meaning "straggling expansion of built-up districts into surrounding countryside" is from 1955.