1. (noun)fluid a substance that is fluid at room temperature and pressure Antonyms: unchangeable, nondisposable, solid, awkward, gaseous
2. (adj)fluid continuous amorphous matter that tends to flow and to conform to the outline of its container: a liquid or a gas Antonyms: awkward, nondisposable, solid, unchangeable, gaseous
1. fluid A fluid is a substance that, like air or water, yields to any force that tends to change its form; a liquid is a body in that state in which the particles move freely among themselves, but remain Synonyms: fluid, gas, liquid