What is another word for "tough"?

Roget's Thesaurus (1911) lists these synonyms for "tough": ant, atomic, blusterer, boaster, braggart, brawler, bulldozer, bully, cartilage, cartilaginous, cement, cohesion, coriaceous, dare-devil, desperado, doctrinaire, dogmatist, drawcansir, eater, fanfaron, fire, fop, fracture, fury, glue, glutinousness, grasp, grip, gristle, gristly, hoodlum, indivisible, jackanapes, jingo, larrikin, leather, leathery, malapert, minx, obstinacy.