leprosy

American  

[lep-ruh-see] / ˈlɛp rə si /

noun

Pathology.

1. a chronic, mildly infectious disease caused by Mycobacterium leprae, affecting the peripheral nervous system, skin, and nasal mucosa and variously characterized by ulcerations, tubercular nodules, and loss of sensation that sometimes leads to traumatic amputation of the anesthetized part.

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leprosy British  

/ ˈlɛprəsɪ /

noun

1. Also called: Hansen's disease.  pathol a chronic infectious disease occurring mainly in tropical and subtropical regions, characterized by the formation of painful inflamed nodules beneath the skin and disfigurement and wasting of affected parts, caused by the bacillus Mycobacterium leprae

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leprosy Scientific  

/ lĕp′rə-sē /

1. A slowly progressive, chronic infectious disease caused by the bacterium Mycobacterium leprae, that damages nerves, skin, and mucous membranes, and can lead to loss of sensation, paralysis, gangrene, and deformity if untreated.

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leprosy Cultural  

1. A chronic and infectious disease, characterized by patches of altered skin and nerve tissue (lesions) that gradually spread to cause muscle weakness, deformities, and paralysis. Some forms of antibiotics are now used to treat this disease, and plastic surgery can help correct the deformities it causes. Also called Hansen's disease.

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Usage

What is leprosy? Leprosy is an infectious disease that causes bumps and wounds on and under the skin that gradually spread and can cause muscle weakness, nerve damage, and paralysis. If not treated effectively, it can result in the loss of body parts and eventually death. Leprosy is also called Hansen’s disease, which is the name preferred by many medical professionals. It’s caused by a kind of bacteria called Mycobacterium leprae. It can be cured with a treatment of antibiotics and other drugs. Cases of leprosy have been documented since ancient times. Due to its severe effects and contagiousness, many people who have had the disease throughout history have been stigmatized and treated as outcasts. Historically, the word leper has been used to refer to a person with leprosy. Due to the stigma, it came to be used in a more figurative way to mean an outcast or someone who is excluded, especially for behavior or opinions considered unacceptable, as in Ever since I expressed my opinion, I’ve been treated like a leper around here. However, both the figurative and literal senses of the word can be considered insensitive due to the fact that they can dehumanize those who have the disease. It is typically recommended to use a phrase like “a person with Hansen’s disease” when referring to someone with the disease.

Discover More

Leprosy has been well known since ancient times, when widespread fear of those afflicted with the disease caused them to be treated as outcasts. Today, the term leper is often used to refer to a person excluded from society.

Other Word Forms

• antileprosy adjective
• leprotic adjective

Etymology

Origin of leprosy

First recorded in 1525–35; perhaps from Medieval Latin leprōsia (recorded only as synonym for leprosarium ), from Greek léprōs(is) “leprosy” + -ia -y ³

Explanation

Leprosy is a horrible and chronic contagious disease that involves the rotting of flesh. There are many terrible diseases in the world, but one of the very worst is leprosy. This bacterial disease is caused by the bacillus Mycobacterium leprae. Leprosy occurs in tropical and subtropical areas, and it's a chronic disease, meaning it doesn't go away. The flesh and organs of a person with leprosy waste away, kind of like a dead person’s. Leprosy also involves inflamed white sores forming underneath the skin. Someone with leprosy is called a leper.

Example Sentences

Cities tended to have higher population density, which could increase the spread of diseases such as leprosy and tuberculosis.

From Science Daily • Mar. 13, 2026

Because people with leprosy or tuberculosis still appeared in prestigious burial areas, the researchers believe this difference likely reflects varying levels of exposure to tuberculosis rather than social stigma.

From Science Daily • Mar. 13, 2026

Although he went on to study cancer, developmental disabilities and ultimately leprosy, the T cell remained at the heart of his scientific inquiries.

From The Wall Street Journal • Dec. 23, 2025

"We have thousands of newly diagnosed leprosy patients across various cities who are just waiting for this drug," he told the BBC.

From BBC • Mar. 8, 2025

He gave a heavy sigh and then said, “Do you know what leprosy is?”

From Full of Beans by Jennifer L. Holm