- [noun] a substance that is fluid at room temperature and pressure
- [noun] a continuous amorphous substance that tends to flow and to conform to the outline of its container: a liquid or a gas
- [adjective] subject to change; variable; "a fluid situation fraught with uncertainty"; "everything was unstable following the coup"
- [adjective] characteristic of a fluid; capable of flowing and easily changing shape
- [adjective] smooth and unconstrained in movement; "a long, smooth stride"; "the fluid motion of a cat"; "the liquid grace of a ballerina"; "liquid prose"
Synonyms: flowing, fluent, liquid, smooth
- [adjective] in cash or easily convertible to cash; "liquid (or fluid) assets"
- [adjective] affording change (especially in social status); "Britain is not a truly fluid society"; "upwardly mobile"