fungal infection [L, fungus, mushroom, inficere, to stain] , any inflammatory condition caused by a fungus. Most fungal infections are superficial and mild, though persistent and difficult to eradicate. Some, particularly in older, debilitated, or immunosuppressed or immunodeficient people, may become systemic and life threatening. Kinds include aspergillosis, blastomycosis, candidiasis, coccidioidomycosis, histoplasmosis.