Lewis & Short

absinthĭum, i, n. (also absinthĭus, i, m., ap. Varr. acc. to Non. 190, 25), = ἀψίνθιον, wormwood, Plin. 27, 7, 28 sq.; Cato, R. R. 159; Varr. R. R. 1, 57; Col. 12, 35; Plaut. Trin. 4, 2, 90: tetrum, Lucr. 1, 936; 2, 400; 4, 11 al.
Trop. for something bitter, but wholesome, Quint. 3, 1, 5.