fluid

(noun) a substance that is fluid at room temperature and pressure.

(noun) continuous amorphous matter that tends to flow and to conform to the outline of its container: a liquid or a gas.

(adj) subject to change; variable. Synonyms: unstable. Examples: "A fluid situation fraught with uncertainty." "Everything was unstable following the coup."

(adj) characteristic of a fluid; capable of flowing and easily changing shape. Synonyms: runny.

(adj) smooth and unconstrained in movement. Synonyms: fluent, liquid, smooth. Examples: "A long, smooth stride." "The fluid motion of a cat." "The liquid grace of a ballerina."

(adj) in cash or easily convertible to cash. Synonyms: liquid. Example: "Liquid (or fluid) assets."

(adj) affording change (especially in social status). Synonyms: mobile. Examples: "Britain is not a truly fluid society." "Upwardly mobile."