[ boi-uhn-see, boo-yuhn-see ]
See synonyms for: buoyancybuoyancies 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.

  1. lightness or resilience of spirit:Student well-being and buoyancy are especially important because of the relatively high incidence of depression and suicide.

Origin of buoyancy

First recorded in 1705–15; buoy(ant) + -ancy
  • Also buoy·ance .

Other words from buoyancy

  • non·buoy·an·cy, noun

Words Nearby buoyancy

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use buoyancy in a sentence

British Dictionary definitions for buoyancy


/ (ˈbɔɪənsɪ) /

  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

  1. the ability to recover quickly after setbacks; resilience

  2. 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

Scientific definitions for buoyancy


[ boiən-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.

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

Cultural definitions for buoyancy


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.