buoyancy

American  

[boi-uhn-see, boo-yuhn-see] / ˈbɔɪ ən si, ˈbu yən si /

Also buoyance

noun

1. the power to float or rise in a fluid; relative lightness.

2. the power of supporting a body so that it floats; upward pressure exerted by the fluid in which a body is immersed.

3. lightness or resilience of spirit.

   Student well-being and buoyancy are especially important because of the relatively high incidence of depression and suicide.

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buoyancy British  

/ ˈbɔɪənsɪ /

noun

1. the ability to float in a liquid or to rise in a fluid

2. the property of a fluid to exert an upward force (upthrust) on a body that is wholly or partly submerged in it

3. the ability to recover quickly after setbacks; resilience

4. cheerfulness

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buoyancy Scientific  

/ boi′ən-sē /

1. The upward force that a fluid exerts on an object that is less dense than itself. Buoyancy allows a boat to float on water and provides lift for balloons.

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buoyancy Cultural  

1. The force that causes objects to float. According to the principle of Archimedes, when a solid is placed in a fluid (a liquid or a gas), it is subject to an upward force equal in magnitude to the weight of the fluid it has displaced.

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Other Word Forms

• nonbuoyancy
  noun

Etymology

Origin of buoyancy

First recorded in 1705–15; buoy(ant) + -ancy

Explanation

Buoyancy is a quality that makes things float in water. It's also a type of happiness: if you're full of buoyancy, your mood is light and happy. This is a word with two main meanings that fit together well: Both kinds of buoyancy have to do with floating and staying up. The physical kind refers to objects that float instead of sinking in water, like a life raft or a buoy. The other kind of buoyancy is a happy mood, a feeling that nothing can get you down. So whenever you run into the word buoyancy, just think "staying afloat."

Example Sentences

It’s easily the best song on the album, and provides a rare moment of buoyancy.

From The Wall Street Journal • Mar. 3, 2026

"We tested them in some really rough environments for weeks at a time and found no degradation to their buoyancy," says Guo.

From Science Daily • Jan. 30, 2026

Trading patterns should provide “a natural buoyancy for prices before the cold arrives.”

From Barron's • Nov. 21, 2025

The note of pop accessibility in Taub’s music and the satiric humor of her lyrics add to the buoyancy.

From Los Angeles Times • Nov. 21, 2025

Maybe its buoyancy was going, or maybe the fuel was running low, but either way it hadn’t taken off yet, and it gave him an idea.

From "The Subtle Knife" by Philip Pullman

Related Words

• elasticity
• resilience