buoyancy

noun

buoy·​an·​cy ˈbȯi-ən(t)-sē 

ˈbü-yən(t)-

1

a

: the tendency of a body to float or to rise when submerged in a fluid

testing an object's buoyancy

b

chemistry : the power of a fluid to exert an upward force on a body placed in it

the buoyancy of water

also : the upward force exerted

2

: the ability to recover quickly from depression or discouragement : resilience

his buoyancy of spirit

3

: the property of maintaining a satisfactorily high level (as of prices or economic activity)

betting that the economy will maintain its buoyancy

Examples of buoyancy in a Sentence

the natural buoyancy of cork

The swimmer is supported by the water's buoyancy.

We hope that the economy will maintain its buoyancy.

Recent Examples on the Web

Swimming is metabolically the least expensive (near-neutral buoyancy needs no energy to support bodies), flying costs more, and running is the least efficient mode of animal and human locomotion. — Literary Hub, 22 June 2026

Ammonites used the chambers in their shells to control buoyancy, much like the modern nautilus. — Torben Rick, The Conversation, 18 June 2026

Bereft of its buoyancy and some of its mass, the whale’s remains fall into the cold, dark depths, where decomposition continues. — Encyclopedia Britannica, 18 June 2026

To reduce pressure on the soft seafloor, engineers added a huge block of foam to the heavy collector to give it some buoyancy. — Harry Stevens, New York Times, 3 June 2026

Word History

Etymology

see buoy entry 1

First Known Use

1713, in the meaning defined at sense 1a

Kids Definition

buoyancy

noun

buoy·​an·​cy ˈbȯi-ən-sē 

ˈbü-yən-

1

: the tendency of a body to float or to rise when in a fluid

the buoyancy of a cork in water

2

: the power of a fluid to put an upward force on a body placed in it

the buoyancy of seawater