1. A skin condition in which there is loss of pigment (color) from areas of skin, resulting in irregular white patches that feel like normal skin: Shortly after he entered his teen years, Ashton noticed the development of vitiligo on his back.
2. A condition in which skin turns white due to the loss of melanocytes also known as leukoderma: Mark received a series of treatments for the vitiligo which was especially noticeable on his right arm.

In vitiligo, the melanocytes, or pigment that gives the skin its normal color, are mysteriously destroyed, leaving depigmented patches of skin on different parts of the body. The hair that grows in areas affected by vitiligo may also turn white.

Vitiligo is more noticeable in darker skinned people because of the contrast of white patches against dark skin.

As the skin gradually loses its color, patch by patch, other people often treat the person with vitiligo like a leper, thinking he/she has a contagious skin disease. In fact, vitiligo is called "white leprosy" in India. Women with it are often discriminated against in marriage. If they develop vitiligo after marriage, it can be grounds for divorce.

3. Etymology: Latin vitiligo, "a kind of tetter" (any of various skin diseases; such as, eczema, psoriasis, or herpes, characterized by eruptions and itching); coined by Aulus Cornelius Celsus, a Roman physician and writer of the early first century; from vitium, "fault, blemish, taint".