brown fat

American  

noun

1. brownish-yellow adipose tissue in the upper back, or interscapular, region of many mammals, most conspicuously in hibernating species and human newborns, composed of numerous innervated fat cells that can produce heat during cold stress; thermogenic tissue.

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brown fat British  

noun

1. tissue composed of a type of fat cell that dissipates as heat most of the energy released when food is oxidized; brown adipose tissue. It is present in hibernating animals and human babies and is thought to be important in adult weight control

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Etymology

Origin of brown fat

First recorded in 1950–55

Example Sentences

When exposed to cold, brown fat uses glucose and lipids to produce heat through a process called thermogenesis.

From Science Daily • Mar. 28, 2026

In contrast, brown fat is present in smaller amounts and plays a specialized role in controlling body temperature and supporting metabolic health.

From Science Daily • Mar. 28, 2026

In contrast, targeting brown fat could increase how much energy the body uses.

From Science Daily • Mar. 28, 2026

Unlike white fat, which stores energy, or muscle, which uses it immediately, brown fat helps keep the body warm in cold environments.

From Science Daily • Oct. 9, 2025

They are about an inch long, gray and brown, fat and greasy-looking.

From Ontario Teachers' Manuals: Nature Study by Ontario. Ministry of Education