Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
mūrĭcīdus (murric-), i, m. [perh. mus-caedo, mouse-killer], a coward, poltroon, as a term of abuse: vae tibi muricide homo, Plaut. Ep. 3, 1, 12; cf. Paul. ex Fest. p. 125 Müll.