Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
sēmĭ-tectus, a, um, adj. [tego], halfcovered (post-Aug.): nudis scapulis aut semitectis, Sen. Vit. Beat. 25, 2 fin.: capuli, App. M. 4, p. 150, 27: femora (Dianae), Arn. 6, 209: exercitus, Amm 19, 11 fin.