"reddish-brown," 1782, from Latin rufus "red, reddish, tawny, red-haired," from an Osco-Umbrian cognate of Latin ruber "red" (from PIE root *reudh- "red, ruddy").
rueful
ruefully
ruff
ruffian
ruffle
rufous
Rufus
rug
rugae
rugby
rugged