leucism

noun

leu·​cism ˈlü-ˌsi-zəm 

: an abnormal condition of reduced pigmentation affecting various animals (such as birds, mammals, and reptiles) that is marked by overall pale color or patches of reduced coloring and is caused by a genetic mutation which inhibits melanin and other pigments from being deposited in feathers, hair, or skin

leucistic

lü-ˈsi-stik 

adjective

Examples of leucism in a Sentence

Recent Examples on the Web

According to the San Diego Zoo Wildlife Alliance, their snowy feathers are the result of a rare genetic condition called leucism, which reduces pigmentation in the plumage while leaving the birds with their normal eye color. — Moná Thomas, PEOPLE, 26 June 2026

Some studies suggested potential ecological costs, but others, including our own work on deep-sea species such as the angular rough shark, showed that conditions like albinism or leucism do not necessarily compromise overall health. — Melissa Cristina Márquez, Forbes.com, 29 May 2026

White bison can occur through several rare genetic conditions, including leucism, which reduces pigmentation but does not necessarily produce a true albino animal. — Nick El Hajj, Des Moines Register, 8 May 2026

There are a variety of causes of leucism, such as genetic, autoimmune and other disorders that result in a partial loss of melanin, Norton said. — Natalie Davies, Freep.com, 22 Oct. 2025

Word History

Etymology

borrowed from German Leucismus, from Greek leukós "clear, white" + German -ismus -ism — more at light entry 1

First Known Use

1878, in the meaning defined above

Rhymes for leucism

• ism
• prism
• schism
• abolitionism
• aldosteronism
• americanism
• anticommunism
• antisemitism
• antiterrorism
• bioterrorism
• colloquialism
• colonialism