- any of various funguslike organisms belonging to the phylum Myxomycota, of the kingdom Protista (or the plant class Myxomycetes), characterized by a noncellular, multinucleate, creeping somatic phase and a propagative phase in which fruiting bodies are produced bearing spores that are covered by cell walls.
- any of several similar organisms of the phylum Acrasiomycota (or class Acrasiomycetes), differing from the true slime molds in being cellular and nucleate throughout the life cycle.
