Lewis & Short

Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.

psythĭus or psĭthĭus, a, um, adj., = ψύθιος (ψιθ-), psythian, a designation of a species of vine: vitis, Verg. G. 4, 269; Col. 3, 2, 24.
Called also simply psythĭa, ae, f., Verg. G. 2, 93; and in plur.: psythiae (sc. uvae), Stat. S. 4, 9, 38.
Neutr. subst.: psythĭum, ii, a kind of raisin-wine, Plin. 14, 9, 11, § 80.