obesity

noun

obe·​si·​ty ō-ˈbē-sə-tē 

: a condition characterized by the excessive accumulation and storage of fat in the body

Obesity affects not just appearance, but disease processes as well.

—Malorye Allison

Synonyms

• fatness
• fat
• weight
• adiposity
• corpulence

Examples of obesity in a Sentence

obesity has been linked to a number of health risks, such as heart disease

Recent Examples on the Web

The vagus nerve also carries fullness signals from the stomach lining to the brain, and a VNS implant has been shown to reduce hunger and promote modest weight loss in obesity. —Clarissa Brincat, Popular Science, 25 Sep. 2025

Prolonged sitting has been associated with obesity, diabetes and cardiovascular diseases. —Jack McNamara, CNN Money, 25 Sep. 2025

The drugmaker said earlier this week that its CT-388 weight loss injection was entering a phase III trial — the final stage before a company can seek regulatory approval — marking the latest development in Roche's nascent but fast-growing pipeline of treatments for obesity and related conditions. —Karen Gilchrist, CNBC, 25 Sep. 2025

Many of the struggles that children face—obesity, isolation, mental-health challenges—are knotty problems without easy answers. —Dhruv Khullar, New Yorker, 24 Sep. 2025

Word History

Etymology

borrowed from Middle French & Latin; Middle French obesité, borrowed from Latin obēsitāt-, obēsitās, from obēsus "fat, stout" + -itāt-, -itās -ity — more at obese

First Known Use

circa 1611, in the meaning defined above

Phrases Containing obesity

• anti-obesity

Medical Definition

obesity

noun

obe·​si·​ty ō-ˈbē-sət-ē 

plural obesities

: a condition that is characterized by excessive accumulation and storage of fat in the body and that in an adult is typically indicated by a body mass index of 30 or greater