trux: truculentus (both mostly in poetry, but also Ciceronian, quam teter incedebat, quam truculentus, quam terribilis aspectu, Sest., 8, 19): torvus (poetical and post-Augustan, prose): ferox. A grim look, vultus torvus, trux; oculi truces; truculenti oculi (Plaut., Asia. 2, 3, 21); aspectus trux (Pacuvius, ap. Cic.). To put on as grim a look as possible against anybody, quam truculentissime aliquem aspicere: from this grim tribune, ab hoc horrido ac truce tribuno plebis (Cic.): to look grim (= sour), vultus acerbos or tristes sumsisse.