Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
tough [tʌf] adj (strong, hard-wearing, material) кре́пкий*кре́пок , про́чный*про́чен (meat, policies, negotiations) жёсткий#; (person, physically) выно́сливый/выно́слив (:mentally) сто́йкий*сто́ек (task, problem, journey) тяжёлый/тяжёл (rough) опа́сный*опа́сен
tough luck! не везёт!
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.