blue mold

Century Dictionary and Cyclopedia

1. n. A common minute fungus, Penicillium crustaceum, of bluish or greenish color, found on moldy bread and a large number of foods and other substances. The mycelium or spawn sends up numerous slender filaments or hyphæ, which branch at the top and bear chains of reproductive cells or conidia. In rare cases spores are produced in asci.

GNU Webster's 1913

1. adj. the blue fungus (Aspergillus glaucus) which grows on cheese.