Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
cādūcĕum, i, n. (sc. sceptrum or baculum), or cādūcĕus, i, m. (sc. scipio or baculus; which form was predominant in the class. per. is doubtful, since neither Cicero, Nepos, Livy, nor Pliny uses the word in the nom.) [kindr. with κηρύκειον, Æolic καρύκιον, —ῦ—, r changed to d, as ad = ar], a herald’s staff, the token of a peaceable embassy (orig. an olive- stick, with στέμματα, which afterwards were formed into serpents, O. Müll. Archaeol. § 379, 3): caduceus pacis signum, Var. de Vita Pop. Rom.lib. ii.; Non. p. 528, 17: caduceo ornatus, * Cic. de Or: 1, 46, 202; so, cum caduceo, Nep. Hann. 11, 1; Liv. 44, 45, 1: caduceum praeferentes, id. 8, 20, 6; Plin. 29, 3, 12, § 54.
Also the staff of Mercury, as messenger of the gods, Macr. S. 1, 19; Hyg. Astr. 2, 7; Serv. ad Verg. A. 4, 242, and 8, 138; Petr. 29, 3; Suet. Calig. 52; App. M. 10, p. 253, 34: Mercuriale, id. ib. 11, p. 262, 4; cf. Dict. Antiq. s. v.; v. also caducifer.