Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
silācĕus or silācĭus, a, um, adj. [1. sil], like ochre, of ochre: color, Plin. 35, 7, 32, § 50: cunei, Vitr. 7, 4; 7, 5.