Try Our Apps


Avoid these words. Seriously.


[boi-uh n-see, boo-yuh n-see] /ˈbɔɪ ən si, ˈbu yən si/
the power to float or rise in a fluid; relative lightness.
the power of supporting a body so that it floats; upward pressure exerted by the fluid in which a body is immersed.
lightness or resilience of spirit; cheerfulness.
Also, buoyance.
Origin of buoyancy
First recorded in 1705-15; buoy(ant) + -ancy
Related forms
nonbuoyancy, noun Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
Cite This Source
Examples from the Web for buoyancy
Contemporary Examples
Historical Examples
  • It may have been the gradient of the hills, but somehow her gait had lost something of its buoyancy.

    The Law-Breakers Ridgwell Cullum
  • He mingled a certain frowning impatience with the buoyancy of his smile.

    The Market-Place Harold Frederic
  • The buoyancy of their irresponsible natures was reasserting itself.

    The Golden Woman Ridgwell Cullum
  • But it was the light in their eyes, their grinning faces, the buoyancy of their gait that held him.

    The Golden Woman Ridgwell Cullum
  • They were young still, and the buoyancy of the country they had adopted was in both of them.

    The Greater Power Harold Bindloss
British Dictionary definitions for buoyancy


the ability to float in a liquid or to rise in a fluid
the property of a fluid to exert an upward force (upthrust) on a body that is wholly or partly submerged in it
the ability to recover quickly after setbacks; resilience
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
Word Origin and History for buoyancy

1713, from buoyant + -cy. Figurative sense (of spirits, etc.) is from 1819.

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
buoyancy in Science
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.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
buoyancy in Culture

buoyancy definition

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.

The New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source

Word of the Day

Nearby words for buoyancy

Difficulty index for buoyancy

Some English speakers likely know this word

Word Value for buoyancy

Scrabble Words With Friends