lesion

noun

le·​sion ˈlē-zhən 

1

: injury, harm

2

: an abnormal change in structure of an organ or part due to injury or disease

especially : one that is circumscribed (see circumscribe sense 1) and well-defined

lesioned

ˈlē-zhənd 

adjective

Examples of lesion in a Sentence

Recent Examples on the Web

Once surgeons remove a tumor or cancerous lesion, the companies sequence it, looking for unique cancer mutations. — Mariam Sunny, USA Today, 25 Aug. 2026

Performance in both tasks depends on memories stored in the hippocampus, which the team confirmed by creating a lesion in the region after training, which caused the memories to disappear. — Jacek Krywko, ArsTechnica, 22 Aug. 2026

The most popular methods — cryotherapy, laser ablation, and high intensity focused ultrasound (HIFU) — have decades of history, and the choice of which to use typically depends on the shape and location of the lesion. — Annalisa Merelli, STAT, 21 Aug. 2026

If the infection enters the bloodstream, symptoms also can include fever, chills, low blood pressure and blistering skin lesions. — ABC News, 17 Aug. 2026

Word History

Etymology

Middle English, from Anglo-French, from Latin laesion-, laesio, from laedere to injure

First Known Use

15th century, in the meaning defined at sense 1

Rhymes for lesion

• friesian
• adhesion
• artesian
• cartesian
• cohesion
• elysian
• magnesian
• austronesian
• indonesian
• melanesian
• micronesian
• polynesian

Kids Definition

lesion

noun

le·​sion ˈlē-zhən 

: a change in the structure of a bodily organ or part due to injury or disease

especially : an injured or diseased spot or area clearly marked off from healthy tissue around it

Medical Definition

lesion

1 of 2 noun

le·​sion ˈlē-zhən 

: an abnormal change in structure of an organ or part due to injury or disease

especially : one that is circumscribed and well defined

lesioned

-zhənd 

adjective

lesion

2 of 2 transitive verb

: to produce lesions in (as an animal's brain)

Legal Definition

lesion

noun

le·​sion ˈlē-zhən 

in the civil law of Louisiana : loss from failure to receive a threshold amount or value (as one-half market value) for immovable property conveyed or transferred by a commutative contract (as a sale or exchange)

called also lesion beyond moiety

compare unjust enrichment

Etymology

Anglo-French, damage, injury, from Latin laesio, from laedere to injure