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

If abnormal lesions are found, patients may need additional mammograms, an ultrasound or sometimes a biopsy or MRI to determine if cancer is present. —Aria Bendix, NBC News, 30 Apr. 2024

To access a lesion in the patient’s hippocampus, a surgeon had removed the tissue from their left anterior temporal lobe, a part of the brain thought to play a role in our memory of objects, people, words and facts. —Will Sullivan, Smithsonian Magazine, 10 May 2024

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

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