buoyancy
BOY-uhn-see
/ˈbɔɪ.ən.si/
The ability or tendency to float in water or air or some other fluid; the upward force exerted by a fluid.
Can refer physically to the upward force of a fluid, or metaphorically to a cheerful, resilient attitude.
The story behind the word. The word traces back to the Dutch 'boei' (a float or signal buoy) and Spanish 'boyar' (to float). These words ultimately derived from Latin roots referring to chains or fetters, because early floating navigation markers were chained securely to the sea floor.
Word relationships
- floatability: Floatability is a colloquial term, while buoyancy is the formal physical property and force.
- cheerfulness: Cheerfulness is purely emotional, whereas metaphorical buoyancy implies bouncing back from adversity.
- heaviness: Heaviness is the downward force of gravity, which opposes the upward force of buoyancy.
Commonly confused with
- density: Density is a material property (mass/volume), whereas buoyancy is the resulting upward force exerted on that material by a surrounding fluid.
Word family
- buoyant (adjective): Able or apt to keep afloat; cheerful and optimistic.
- buoyantly (adverb): In a cheerful or floating manner.
Collocations
- neutral buoyancy
- positive buoyancy
- buoyancy force
- maintain buoyancy
Example sentences
- "Sharks rely on their large, oil-filled livers to maintain buoyancy because they lack a bony fish's swim bladder." Marine biology
- "Despite the economic downturn, her natural buoyancy and optimism kept the entire team motivated." Metaphorical resilience
Memory hook
Think of a 'buoy' (boy) bouncing happily up and down on top of the ocean waves. Buoyancy = Buoy bouncing on waves.
When not to use
Avoid using to describe simple lightness of weight without the presence of a supporting fluid medium.
Fun facts
- The Dead Sea has such high salt concentration and density that its natural buoyancy makes it virtually impossible for a human swimmer to sink.
Related words
Take your vocabulary further with LangBlitz
Our English vocabulary app: FSRS spaced repetition, 5,000+ curated words across 119 topic groups, CEFR A1 to C2. Explore your mastery with the beautiful Vocabulary World feature.