| Noun | 1. | fluid - a substance that is fluid at room temperature and pressurematter, substance - that which has mass and occupies space; "an atom is the smallest indivisible unit of matter" coolant - a fluid agent (gas or liquid) that produces cooling; especially one used to cool a system by transfering heat away from one part to another; "he added more coolant to the car's radiator"; "the atomic reactor used a gas coolant"; "lathe operators use an emulsion of oil and water as a coolant for the cutting tool" filtrate - the product of filtration; a gas or liquid that has been passed through a filter liquid - a substance that is liquid at room temperature and pressure | |
| 2. | fluid - a continuous amorphous substance that tends to flow and to conform to the outline of its container: a liquid or a gasmatter, substance - that which has mass and occupies space; "an atom is the smallest indivisible unit of matter" gas - a fluid in the gaseous state having neither independent shape nor volume and being able to expand indefinitely ichor - (Greek mythology) the rarified fluid said to flow in the veins of the Gods liquid - a substance in the fluid state of matter having no fixed shape but a fixed volume | |
| Adj. | 1. | fluid - subject to change; variable; "a fluid situation fraught with uncertainty"; "everything was unstable following the coup"changeful, changeable - such that alteration is possible; having a marked tendency to change; "changeable behavior"; "changeable moods"; "changeable prices" | |
| 2. | fluid - characteristic of a fluid; capable of flowing and easily changing shapeliquid - existing as or having characteristics of a liquid; especially tending to flow; "water and milk and blood are liquid substances" | |
| 3. | fluid - smooth and unconstrained in movement; "a long, smooth stride"; "the fluid motion of a cat"; "the liquid grace of a ballerina"; "liquid prose"graceful - characterized by beauty of movement, style, form etc.; not awkward | |
| 4. | fluid - in cash or easily convertible to cash; "liquid (or fluid) assets"disposable - free or available for use or disposition; "every disposable piece of equipment was sent to the fire"; "disposable assets" | |
| 5. | fluid - affording change (especially in social status); "Britain is not a truly fluid society"; "upwardly mobile"changeful, changeable - such that alteration is possible; having a marked tendency to change; "changeable behavior"; "changeable moods"; "changeable prices" | |