n. A continuous, amorphous substance whose molecules move freely past one another and that has the tendency to assume the shape of its container; a liquid or gas. adj. 1. Of, relating to, or characteristic of a fluid. 2. Readily reshaped; pliable. 3. Smooth and flowing; graceful: the fluid motion of a cat. 4. a. Changing or tending to change; variable: a fluid situation fraught with uncertainty. b. Characterized by or allowing social mobility: a fluid society. 5. Convertible into cash: fluid assets. [From Middle English, flowing, from Old French fluide, from Latin fluidus, from fluere, to flow; see bhleu- in the Appendix of Indo-European roots.] flu·idi·ty (-ĭdĭ-tē), fluid·ness n. fluid·ly adv. |
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.