[boi-uh n-see, boo-yuh n-see]
See more synonyms for buoyancy on Thesaurus.com
  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; cheerfulness.
Also buoy·ance.

Origin of buoyancy

First recorded in 1705–15; buoy(ant) + -ancy
Related formsnon·buoy·an·cy, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for buoyance

Historical Examples of buoyance

  • A buoyance in the very air proclaimed that school days were over.


    Jane Abbott

  • He liked the buoyance of glider flying, the nearest approach of man to the bird, and thus far everything was going well.


    Dallas McCord Reynolds

  • The blow which rendered her without control did not break her spirit, but it pressed out its buoyance.

  • The fur of the coat seemed not to get wet through, and retained a certain amount of air that added to buoyance.

  • This buoyance was interrupted but once, and briefly, ere he gained the haven of his office.

    The Sturdy Oak

    Samuel Merwin, et al.

British Dictionary definitions for buoyance


  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
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

Word Origin and History for buoyance

1821, from buoyant + -ance.



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

Online Etymology Dictionary, © 2010 Douglas Harper

buoyance in Science


  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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

buoyance in Culture


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 Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.