troglodyte

n person living in a cave, esp in prehistoric times 穴居人（尤指史前时期的）.

trippingly, triptych, trisect, trisection, trite, triumph, triumphal, triumphant, triumphantly, triumvirate, trivet, trivia, trivial, triviality, trivialization, trivialisation, trivialize, trivialize, trivialise, trivially, trod, trodden, troika, Trojan, Trojan horse, troll, trolley, trolley bus, trollop, trombone, trombonist, troop, troop-ship, trooper, trope, trophy, tropic, tropical, tropically, troposphere, Trot, troth,