Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† 1. cestus (caest-) or -ŏs, i, m., = κεστός (lit. stitched, embroidered; hence, subst.; cf. Lidd. and Scott under κεστός), a girdle, tie, belt, girth, strap, Cato, R. R. 25 Schneid. N. cr.; Varr. R. R. 1, 8, 6.
Particularly, the girdle of Venus, Mart. 6, 138; 6, 14; 14, 206 sq.; Serv. ad Verg. A. 5, 69.