Pronunciation: (flOO'id), [key]
a substance, as a liquid or gas, that is capable of flowing and that changes its shape at a steady rate when acted upon by a force tending to change its shape.
1. pertaining to a substance that easily changes its shape; capable of flowing.
2. consisting of or pertaining to fluids.
3. changing readily; shifting; not fixed, stable, or rigid: fluid movements.
4. convertible into cash: fluid assets.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.