Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
mūcĭdus (mucc-), a, um, adj. [mucus]. 
- I.  Mouldy, musty: mucida panis frusta, Juv. 14, 128: vina, Mart. 8, 6, 4.
 
- II.  Snivelling: homo es, Qui me emunxisti mucidum, Plaut. Epid. 3, 4, 58: senex, id. Mil. 3, 1, 52.