fluid

a substance that is fluid at room temperature and pressure

a continuous amorphous substance that tends to flow and to conform to the outline of its container: a liquid or a gas

subject to change; variable

• “a fluid situation fraught with uncertainty”
• “everything was unstable following the coup”

characteristic of a fluid; capable of flowing and easily changing shape

smooth and unconstrained in movement

• “a long, smooth stride”
• “the fluid motion of a cat”
• “the liquid grace of a ballerina”
• “liquid prose”

in cash or easily convertible to cash

• “liquid (or fluid) assets”

affording change (especially in social status)

• “Britain is not a truly fluid society”
• “upwardly mobile”