melanosis

noun Pathology.

1. abnormal deposition or development of black or dark pigment in the tissues.
2. a discoloration caused by this.

noun

1. pathol a skin condition characterized by excessive deposits of melanin

n.1823, medical Latin, from Greek melanosis “a becoming black,” from melanoun “to become black,” from melas (genitive melanos); see melanin. Related: Melanotic. n.

1. Abnormally dark pigmentation of the skin or other tissues, resulting from a disorder of pigment metabolism.melanism