Source : Webster's Revised Unabridged Dictionary (1913)

Melasma \Me*las"ma\, n. [NL., fr. Gr. ? black spot.] (Med.)
   A dark discoloration of the skin, usually local; as,
   Addison's melasma, or Addison's disease. -- {Me*las"mic}, a.

Source : WordNet®

melasma
     n : a tan discoloration of a woman's face that is associated
         with pregnancy or with the use of oral contraceptives
         [syn: {chloasma}, {mask of pregnancy}]