Old English hreaw "uncooked, raw," from Proto-Germanic *khrawaz (source also of Old Norse hrar, Danish raa, Old Saxon hra, Middle Dutch rau, Dutch rauw, Old High German hrawer, German roh), from PIE root *kreue- "raw flesh."
Meaning "tender, sore" is from late 14c.; of persons, "inexperienced" from 1560s; of weather, "damp and chilly" first recorded 1540s. Related: Rawly; rawness. Raw material is from 1796, with sense of "in a rudimental condition, unfinished." Phrase in the raw "naked" (1921) is from the raw "exposed flesh," attested from 1823. Raw deal "harsh treatment" attested by 1893.