nounWord forms: plural -cilliums or -cillia (-ˈsɪlɪə)any ascomycetous saprotrophic fungus of the genus Penicillium, which commonly grow as a green or blue mould on stale food: some species are used in cheese-making and others as a source of penicillin
Word origin
C19: New Latin, from Latin
pēnicillus tuft of hairs; named from the tufted appearance of the sporangia of this fungus