Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
sēmĭ-cinctĭum, ii, n., a semi-girdle, a narrow girdle or apron, Mart. 14, 153 in lemm.; Petr. 94, 8 (al. hemicyclo); Isid. Orig. 19, 33; Vulg. Act. 19, 12; cf. semifunium.