Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
sēmĭ-nĕcis, is (nom. does not occur), adj. [nex], half-dead (not ante-Aug.; syn. semivivus): alicui semineci rapere arma, Verg. A. 10, 462: seminecem eum ad Cannas in acervo caesorum corporum inventum, Liv. 23, 15; so, seminecem, id. 29, 2 fin.; Verg. A. 5, 275; Ov. Tr. 5, 9, 19: vita, Sil. 10, 456: semineces, Verg. A. 9, 455; 12, 329: artus, Ov. M. 1, 228: crines, Val. Fl. 6, 176; Tac. Agr. 36; id. H. 3, 28: seminecum, Sil. 4, 164; 6, 11.