float
To be supported by a fluid of greater density (than the object).
Example
“Helium balloons float in air, while air-filled balloons don't.”
Other meanings
To be supported by a liquid of greater density, such that part (of the object or substance) remains above the surface.
To cause something to be suspended in a fluid of greater density.
“to float a boat”
Word history
From Old English "flotian" (to float).
Where this comes from
This definition is adapted from “float” on Wiktionary, by its contributors, published under CC BY-SA 4.0. This page is published under the same licence.