(not comparable) Of or relating to fluid. / In a state of flux; subject to change. / Moving smoothly, or giving the impression of a liquid in motion. / (of an asset) Convertible into cash.

Any substance which can flow with relative ease, tends to assume the shape of its container, and obeys Bernoulli's principle; a liquid, gas or plasma. / A liquid (as opposed to a solid or gas).

plural of fluid

The quality of being fluid.

plural of fluid ounce

Any of various units of volume used for liquid measure, all approximately 1.73–1.83 cubic inches or 28.4–30 milliliters.

(anatomy) Any liquid portion of the body, such as blood, urine, semen, saliva, especially when expelled.

(medicine) A clear bodily fluid in the form of a very pure saline solution with microglia that occupies the subarachnoid space in the brain (between the skull and the cerebral cortex), and which acts as a cushion or buffer for the cortex.

(mechanics) The branch of mechanics dealing with gases and liquids, either at rest or in motion.

The clear, colorless, viscous fluid that is secreted from an aroused penis before ejaculation.