|mold (mōld) Pronunciation Key
Any of various fungi that often form a fuzzy growth (called a mycelium) on the surface of organic matter. Some molds cause food to spoil, but others are beneficial, such as those used to make certain cheeses and those from which antibiotics like penicillin are developed. The molds do not form a distinct phylogenetic grouping but belong to various phyla including the ascomycetes and the zygomycetes. See also slime mold.