buoyancy

American  

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

Also buoyance

noun

buoyancies plural

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.

---

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

---

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.

---

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.

---

Other Word Forms

Derived Forms

• nonbuoyancy
  noun

Inflected Forms

Nouns

• buoyancies
  plural

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

Suzuki exudes the fragility and buoyancy of adolescence, playing Fuki as someone constantly imbibing the world, rarely revealing what she’s doing with that stimulus.

From Los Angeles Times • Jun. 5, 2026

The intervening years had brought major advances: better copper wires, improved insulation and increased buoyancy.

From The Wall Street Journal • Jun. 4, 2026

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

From BBC • Feb. 20, 2026

Markets elsewhere, bereft of megacap tech buoyancy, failed to keep pace.

From Barron's • Feb. 18, 2026

They dispersed about the room, reminding me, by the lightness and buoyancy of their movements, of a flock of white plumy birds.

From "Jane Eyre" by Charlotte Brontë

Related Words

• elasticity
• resilience