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
Examples of leucism in a Sentence
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However, leucism — a separate condition — can also produce white coloration in whales, according to LiveScience, meaning not all whales with an ivory complexion are true albinos.
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Brendan Rascius, Miami Herald, 30 June 2025
The orca's pale complexion may be due to leucism or Chediak-Higashi Syndrome.
—Fernando Cervantes Jr., USA TODAY, 5 Dec. 2024
This discrepancy surprised us because the genetic mutation that causes melanism occurs less frequently than the one that causes albinism/leucism.
—Elizabeth Carlen, Discover Magazine, 31 Oct. 2024
On social media, some commenters speculated the creature might be a young red or gray fox with leucism, a condition that causes a loss of pigmentation, resulting in white fur.
—Alexa Robles-Gil, Smithsonian Magazine, 17 Oct. 2024
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Brendan Rascius, Miami Herald, 30 June 2025
The orca's pale complexion may be due to leucism or Chediak-Higashi Syndrome.
—Fernando Cervantes Jr., USA TODAY, 5 Dec. 2024
This discrepancy surprised us because the genetic mutation that causes melanism occurs less frequently than the one that causes albinism/leucism.
—Elizabeth Carlen, Discover Magazine, 31 Oct. 2024
On social media, some commenters speculated the creature might be a young red or gray fox with leucism, a condition that causes a loss of pigmentation, resulting in white fur.
—Alexa Robles-Gil, Smithsonian Magazine, 17 Oct. 2024
See All Example Sentences for leucism
Cite this Entry
“Leucism.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/leucism. Accessed 20 Jul. 2025.
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