Meaning of FLUID in English

I. ˈflüə̇d adjective

Etymology: French or Latin; French fluide, from Latin fluidus, from fluere to flow; akin to Greek phlyein, phlyzein to boil over, chatter, Latin flare to blow — more at blow

1. : 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


a. : likely to change or move : not fixed or rigid

a fluid military situation

b. : characterized by or employing a smooth easy style or producing such an effect especially in literature or art

a fluid style

fluid restful lines

c. : free or tending to alter in form or content

fluid consciousness

d. : available for a different use or application : not currently pledged or firmly engaged

fluid capital

especially : such as may be rapidly or immediately converted into cash

fluid assets

e. : shifting from place to place : mobile

the fluid population of large cities


a. : of, relating to, or like a fluid

b. : characteristic of a fluid

the fluid state

c. : employing, based on, or acting through or like a fluid or the fluid state

fluid power

fluid catalytic cracking of oil

— compare fluidize ; see fluid catalyst

Synonyms: see liquid

II. noun

( -s )

1. : a substance that alters its shape in response to any force however small, that tends to flow or to conform to the outline of its container, and that includes gases and liquids and in strictly technical use certain plastic solids and mixtures of solids and liquids capable of flow

2. : a nonsolid substance in the body of an animal or a plant

cerebrospinal fluid

body fluids

3. : a hypothetical substance to which a particular phenomenon (as heat or electricity) was formerly attributed

Webster's New International English Dictionary.      Новый международный словарь английского языка Webster.