Roscius, Quintus, << ROSH ee uhs, KWIHN tuhs >> (126? B.C.-62? B.C.), a Roman actor, was so famous in his day that his name came to stand for “great actor.” He excelled in both tragic and comic parts. He founded a school for actors and wrote a book on acting and speaking. One of his admirers was the orator Cicero, who defended him in a famous speech. Quintus Roscius Gallus was born near Rome and became rich through his acting.