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.

Gordĭum, ii, n., = Γόρδιον, a city of Phrygia Major on the Sangarius, famous for the Gordian knot (v. Gordius), Plin. 5, 32, 42, § 146; Liv. 38, 18, 10 sqq.; Curt. 3, 1, 12 sqq.
Hence, Gordĭensis, e, adj., of Gordium, Scrib. 172.

Gordĭus, ii, m., = Γόρδιος, a king of Gordium, in Phrygia Major, famous for the inextricable knot on his chariot, which Alexander the Great cut with his sword, Curt. 3, 1, 15 sqq.; Just. 11, 7, 13 sqq.
Hence, Gordĭus, a, um, adj., of or belonging to Gordius: nodus, i. e. an insoluble problem, Amm. 14, 11, 1.