fluct-, flucti-, -flux, flu-, flum-, -fluent, -fluence

(Latin: flow, flowing; moving in a continuous and smooth way; wave, moving back and forth)

fluency
1. The quality of flowing, applied to speech or language; smoothness; freedom from harshness; as fluency of numbers.
2. Readiness of utterance; facility of words; volubility; as fluency of speech; a speaker of remarkable fluency: "Students must demonstrate fluency in a foreign language to earn a degree."
fluent
1. The ability to speak a language effortlessly and correctly.
2. Flowing in a smooth and graceful way; such as, a yacht with long, fluent curves.
3. Flowing or capable of flowing; such as, being fluid.
4. Etymology: from 1589, which came from Latin fluentem, fluens, present participle of fluere, "to flow".
fluent aphasia
1. Aphasia characterized by fluent but meaningless speech and severe impairment of the ability to understand spoken or written words.
2. A condition in which speech is well articulated (usually 200 or more words per minute) and grammatically correct, but which is lacking in content and meaning.
fluently
1. Without hesitation or obstruction; such as, to speak fluently.
2. Smooth and unconstrained in movement.
3. Expressing oneself readily, clearly, and effectively.
fluid
1. A substance whose molecules flow freely, so that it has no fixed shape and little resistance to outside stress: "Capable of flowing freely like water."
2. A substance that is able to flow freely; a liquid substance: "Please check the fluids in the car's engine."
3. A non-solid state of matter in which the atoms or molecules are free to move past each other; such as, in a gas or a liquid.
4. Used to describe something that can change easily or that changes often: "Boundaries between the farms were very fluid."
fluid dynamics
The scientific study of fluids in motion; such as, gases and liquids.
fluid geometry
The distribution of fluids in the rocks of a reservoir, as influenced by the rock's composition, porosity, method of producing saturation, and the degree of moisture characteristics.
fluid mechanics
1. The scientific study of the mechanical properties of fluids (gases and liquids) in motion or at rest, including the observation, description, and mathematical computation of the behavior of fluids.
2. The experimental and mathematical-computational study of the mechanical behavior of fluids.

Fluid mechanics includes the transfer of heat and matter resulting from motion of the fluid, and the driving of the fluid motion due to differences in density which may be induced by temperature, as well as the effects due to temperature dependency of the constants of materials; for example, the viscosity.

3. The study of fluids and gases at rest and in motion which can be divided into hydrostatics, the behavior of liquids at rest; hydrodynamics, the behavior of liquids in motion; and aerodynamics, the behavior of gases in motion.

Hydrostatics takes into account the forces exerted by a liquid in all directions, not just the downward gravitational pull; such as, the upward force exerted on a submerged object that causes bouyancy.

Hydrodynamics is the study of fluid flow and fluid friction, or viscosity.

Aerodynamics is the study of the motion of gases which is most often applied to the study of air and the motion of solid bodies in it.

—Excerpts from "Fluid Mechanics", Encyclopedia of Science and Technology;
Routledge; New York; 2001; page 200.
fluid pressure
The pressure exerted by a confined fluid in static equilibrium, equal in all directions and perpendicular to the surface confining it.
fluid-flow analogy
In transportation engineering, a conceptual model of traffic flow based on the behavior of fluids.

The intuitive power of this model is expressed in common terms; such as, "flow" and "bottleneck", but the "fluid-flow analogy" is also used to construct sophisticated models of traffic behavior.

fluidic
1. Relating to fluids; substances, as liquids or gases, that are capable of flowing and that change their shapes at steady rates when acted upon by forces tending to change their shapes.
2. Relating to, or characteristic of a fluid or referring to a substance that easily changes its shape and is capable of flowing.
fluidics, fluidic technology
1. A technology that carries out sensing, control, information processing, and actuation functions with fluid dynamic phenomena rather than mechanical moving parts.
2. The science, or technology, of using tiny jets of a gas or a liquid rather than electronic circuits for sensing, amplifying, or controlling certain functions.
fluidity
1. The ability of a substance to flow; flowing easily.
2. The quality of being capable of flowing; that quality of certain bodies which makes them impressible to the slightest force, and by which the parts easily move or change their relative position without a separation of the mass; a liquid state; as opposed to solidity.
3. Having or showing a smooth and easy style; graceful: "The extreme fluidity of the situation has made it impossible to predict the outcome."
fluidization
1. The process in which a solid is so finely ground as to take on most of the properties of a liquid.
2. A technique in which a finely divided solid is caused to behave in the manner of a fluid by its being suspended in a moving gas or liquid; the solids treated in this way are frequently catalysts.
3. The suspension of solid particles in a rapidly moving stream of gas or vapor to induce flowing motion of the whole.

Specifically, a technique in which a finely divided solid is caused to behave in the manner of a fluid by its being suspended in a moving gas or liquid.

fluidize
To make something fluid; that is, to give fluid properties to (a solid) by means of fluidization, so that it flows when in contact with a liquid or gaseous stream.