A patchy or generalized dark pigmentation of the skin.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Examples from the Web for melasma
Historical Examples of melasma
The color is yellowish, or brownish, and may even be blackish (melasma, melanoderma).Essentials of Diseases of the Skin
Henry Weightman Stelwagon