the appearance on a person's skin, esp of the face, of patches of darker colour: associated with hormonal changes caused by liver disease or the use of oral contraceptives
Word origin
C19: from New Latin, from Greek khloasma greenness
chloasma in American English
(kloʊˈæzmə)
noun
a skin discoloration on the face and chest, resulting from pregnancy, disease, malnutrition, etc.