Why is the ninth month called September?
"rough, shaggy," c.1300, past participle adjective as though from a verb form of rag (n.). Cf. Latin pannosus "ragged, wrinkly," from pannus "piece of cloth." But the word might reflect a broader, older meaning; perhaps from or reinforced by Old Norse raggaðr "shaggy," via Old English raggig "shaggy, bristly, rough" (which, Barnhart writes, "was almost surely developed from Scandinavian"). Of clothes, early 14c.; of persons, late 14c. To run (someone) ragged is from 1915. Related: Raggedly; raggedness.
scrap of cloth, early 14c., probably from Old Norse rögg "shaggy tuft," earlier raggw-, or possibly from Old Danish rag (see rug), or a back-formation from ragged, It also may represent an unrecorded Old English cognate of Old Norse rögg. Watkins traces the Old Norse word through Proto-Germanic *rawwa-, from PIE root *reue- "to smash, knock down, tear up, uproot" (see rough (adj.)).
As an insulting term for "newspaper, magazine" it dates from 1734; slang for "tampon, sanitary napkin" is attested from 1930s (on the rag "menstruating" is from 1948). Rags "personal clothing" is from 1855 (singular), American English. Rags-to-riches "rise from poverty to wealth" is attested by 1896. Rag-picker is from 1860; rag-shop from 1829.
"scold," 1739, of unknown origin; perhaps related to Danish dialectal rag "grudge." Related: Ragged; ragging. Cf. bullyrag, ballarag "intimidate" (1807).