1) A circumscribed melanosis consisting of a brown-pigmented, velvety verrucosity or fine papillomatosis appearing in the axillae and other body folds. It occurs in association with endocrine disorders, underlying malignancy, administration of certain drugs, or as in inherited disorder.

2) A skin disease characterized by gray-black warty patches usually situated in the axilla or groin or on elbows or knees and sometimes associated with cancer of abdominal viscera.