The meaning of FLUID is having particles that easily move and change their relative position without a separation of the mass and that easily yield to pressure : capable of flowing.
In physics, a fluid is a liquid, gas, or other material that may continuously move and deform (flow) under an applied shear stress, or external force. [1] They have zero shear modulus, or, in simpler terms, are substances which cannot resist any shear force applied to them. [citation needed]
fluid adjective (LIKELY TO CHANGE) If situations, ideas, or plans are fluid, they are not fixed and are likely to change, often repeatedly and unexpectedly:
FLUID definition: 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.
fluid (countable and uncountable, plural fluids) 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. quotations
A liquid is a fluid — something that flows easily when poured — although gases can also be called fluid. When your doctor told you to drink lots of fluids to help your cold symptoms, she probably meant things like water or orange juice, not root beer floats.
adj. Hydraulics pertaining to a substance that easily changes its shape; capable of flowing. Hydraulics consisting of or pertaining to fluids. changing readily; shifting; not fixed, stable, or rigid: fluid movements. convertible into cash: fluid assets.