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

The gourd was used as a buoyancy aid and a place to put the catch.

From BBC • Feb. 20, 2026

That earlier design relied on two water-repelling disks sealed together to create buoyancy.

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

Shanti bobbed up and down in the water, enjoying her buoyancy.

From "Beauty Queens" by Libba Bray

Related Words

• elasticity
• resilience