[1] : The Collaborative International Dictionary of English v.0.48

fluid \flu"id\ fl=u"i^d, a. l. fluidus, fr. fluere to
   flow: cf. f. fluide. see fluent.
   having particles which easily move and change their relative
   position without a separation of the mass, and which easily
   yield to pressure; capable of flowing; liquid or gaseous.
   1913 webster
see also:
fluent 

[2] : The Collaborative International Dictionary of English v.0.48

fluid \flu"id\, n.
   a fluid substance; a body whose particles move easily among
   themselves.
   1913 webster

   note: fluid is a generic term, including liquids and gases as
         species. water, air, and steam are fluids. by analogy,
         the term was sometimes applied to electricity and
         magnetism, as in phrases electric fluid, magnetic
         fluid, though not strictly appropriate; such usage has
         disappeared.
         1913 webster +pjc

   fluid dram, or fluid drachm, a measure of capacity equal
      to one eighth of a fluid ounce.

   fluid ounce.
   a in the united states, a measure of capacity, in
       apothecaries' or wine measure, equal to one sixteenth of
       a pint or 29.57 cubic centimeters. this, for water, is
       about 1.04158 ounces avoirdupois, or 455.6 grains.
   b in england, a measure of capacity equal to the twentieth
       part of an imperial pint. for water, this is the weight
       of the avoirdupois ounce, or 437.5 grains.

   fluids of the body. physiol. the circulating blood and
      lymph, the chyle, the gastric, pancreatic, and intestinal
      juices, the saliva, bile, urine, aqueous humor, and muscle
      serum are the more important fluids of the body. the
      tissues themselves contain a large amount of combined
      water, so much, that an entire human body dried in vacuo
      with a very moderate degree of heat gives about 66 per
      cent of water.

   burning fluid, elastic fluid, electric fluid, magnetic
   fluid, etc. see under burning, elastic, etc.
      1913 webster
see also:
fluid dram fluid drachm fluid ounce fluids of the body burning fluid elastic fluid 
electric fluid magnetic fluid burning elastic 

[3] : WordNet (r) 2.0

fluid
     adj 1: subject to change; variable; "a fluid situation fraught with
            uncertainty"; "everything was unstable following the
            coup" syn: unstable
     2: characteristic of a fluid; capable of flowing and easily
        changing shape syn: runny
     3: smooth and unconstrained in movement; "a long, smooth
        stride"; "the fluid motion of a cat"; "the liquid grace of
        a ballerina"; "liquid prose" syn: flowing, fluent, liquid,
         smooth
     4: in cash or easily convertible to cash; "liquid or fluid
        assets" syn: liquid
     5: affording change especially in social status; "britain is
        not a truly fluid society"; "upwardly mobile" syn: mobile
     n 1: a substance that is fluid at room temperature and pressure
     2: a continuous amorphous substance that tends to flow and to
        conform to the outline of its container: a liquid or a gas
see also:
unstable runny flowing fluent liquid smooth 
mobile 

[4] : Moby Thesaurus II by Grady Ward, 1.0

106 moby thesaurus words for "fluid":
   able to adapt, adaptable, adjustable, aerodynamics, afterdamp, air,
   alterable, alterative, aqueous, atmosphere, beverage, blackdamp,
   blood, breath, changeable, changeful, checkered, chokedamp, cloud,
   damp, drink, effluvium, ever-changing, exhalation, fetid air,
   firedamp, flatus, flexible, flowing, fluent, fluid extract,
   fluid mechanics, fluidal, fluidic, fluxible, fluxile, fluxional,
   fluxionary, formless, fume, gas, halogen gas, hydraulics,
   hydrogeology, ichor, impermanent, indefinite, inert gas, juice,
   juicy, kaleidoscopic, latex, liquid, liquid extract, liquidy,
   liquor, malaria, malleable, many-sided, mephitis, mercurial,
   metamorphic, miasma, milk, mobile, modifiable, movable, mutable,
   nonuniform, permutable, plastic, pliant, pneumatics, protean,
   proteiform, puff of smoke, reek, resilient, rubbery, running,
   runny, sap, sappy, semiliquid, shifting, smoke, smudge, solution,
   steam, succulent, supple, transient, transitory, uncertain,
   unfixed, unformed, unsettled, unstable, unsteady, vapor, variable,
   volatile, water, water vapor, watery, whey

Fluid >> F Words
Fluid, definition of term: Fluid
fluid_pag1.html

Fluid Ounce >> F Words
Fluid Ounce, definition of term: Fluid Ounce
fluid+ounce_pag1.html

Amniotic Fluid >> A Words
Amniotic Fluid, definition of term: Amniotic Fluid
amniotic+fluid_pag1.html