<p><strong>Noun</strong></p><ul><li>any of a diverse group of eukaryotic single-celled or multinucleate organisms that live by decomposing and absorbing the organic material in which they grow, comprising the mushrooms, molds, mildews, smuts, rusts, and yeasts, and classified in the kingdom Fungi or, in some classification systems, in the division Fungi (Thallophyta) of the kingdom Plantae.</li><li>a spongy, abnormal growth, as granulation tissue formed in a wound.</li></ul><p><strong>Adjective</strong></p><ul><li>fungal: a fungus infection of the toenails.</li></ul>