Tough  —adj. 1 hard to break, cut, tear, or chew. 2 able to endure hardship; hardy. 3 unyielding, stubborn, difficult (it was a tough job). 4 colloq. A acting sternly; hard (get tough with). B (of circumstances, luck, etc.) Severe, hard. 5 colloq. Criminal or violent. —n. Tough person, esp. A ruffian.  toughen v. Toughness n. [old english]