O.E. toh "difficult to break or chew," from P.Gmc. *tankhuz (cf. M.L.G. tege, M.Du. taey, Du. taai, O.H.G. zach, Ger. zäh). See rough for spelling change. Figurative sense of "strenuous, difficult, hard to beat" is first recorded c.1200; that of "hard to do, trying, laborious" is from 1619. The noun meaning "street ruffian" (U.S.) is from 1866. Toughen is attested from 1580s. Verb tough it "endure the experience" is first recorded 1830, Amer.Eng. Tough guy first recorded 1932. Tough-minded first recorded 1907 in William James. Tough luck first recorded 1912; tough shit is from 1946.