Lewis & Short

tyrannĭcus, a, um, adj., = τυραννικός, tyrannous, tyrannical: tetrum facinus, crudele, nefarium, tyrannicum, Auct. Her. 2, 30, 49: leges, Cic. Leg. 1, 15, 42: ira, Sen. Ben. 1, 11, 2: crudelitas, Just. 16, 4, 11: dominatio, id. 16, 4, 16: vitia, id. 21, 5, 9: regia et paene tyrannica facere, Eutr. 6, 25.
Adv.: tyrannĭcē, tyrannically: ea quae regie seu potius tyrannice statnit, Cic. Verr. 2, 3, 48, § 115.