The spelling of the word "leucasmus" can be explained using IPA phonetic transcription. The word is pronounced as "loo-kuh-smuhs" with the stress on the first syllable. The "eu" in the middle of the word is pronounced like "yoo" in "you" and is followed by a "k" sound. The "as" at the end of the word is pronounced as "uhs". The term "leucasmus" is derived from the Greek words "leucos" meaning white and "asmus" meaning shield, and is used to describe a white patch in the eye's iris.
Vitiligo.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.