What does Boxing Day have to do with boxing?
"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.