名詞 fluid:

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

形容詞 fluid:

1. subject to change; variable
   同義詞：unstable
2. characteristic of a fluid; capable of flowing and easily changing shape
   同義詞：runny
3. smooth and unconstrained in movement
   同義詞：fluent, liquid, smooth
4. in cash or easily convertible to cash
   同義詞：liquid
5. affording change (especially in social status)
   同義詞：mobile

1. Air is a fluid but not a liquid, while water is both a fluid and a liquid.
   空氣是流體不是液體，水是流體也是液體。
2. Did the cleaning fluid work (on that stain)? ie Did it remove it?
   這種洗滌劑(對那塊污斑)管用嗎?
3. The rate of flow of fluid, particles, or energy through a given surface.
   流動率流體、微粒或能量通過一設(shè)定的表面時流動的速率
4. Air whether in the gaseous or liquid state is a fluid.
   空氣，無論是氣態(tài)的還是液態(tài)的，都是一種流體。

flu.id

n.Abbr. fl,fl.（名詞）縮寫 fl,fl.
A continuous, amorphous substance whose molecules move freely past one another and that has the tendency to assume the shape of its container; a liquid or gas.
流體：一種分子之間能自由移動并有隨容器形狀變化趨勢的連續(xù)的、無定形的物質(zhì)；液體或氣體
adj.（形容詞）
Of, relating to, or characteristic of a fluid.
流體的：流體的、有關(guān)流體的或有流體特性的
Readily reshaped; pliable.
易被重塑的；柔韌的
Smooth and flowing; graceful:
流暢的，優(yōu)美的：順暢而有流動感的；優(yōu)雅的：
例句：
the fluid motion of a cat.
貓的優(yōu)美動作

Changing or tending to change; variable:
變化的：變化的或有變化趨勢的；可變的：
例句：
a fluid situation fraught with uncertainty.
充滿不穩(wěn)定因素的動蕩局勢

Characterized by or allowing social mobility:
社會脈動的：以社會可動性為特征的或允許社會變動的：
例句：
.Everyone seems to . . . share in an intricate set of lore from the past and present whose deliciousness somehow would be ruined if Britain were a truly fluid society.(Nicholas Lemann)
.每個人看上去…都擁有這樣一套從過去和現(xiàn)在的經(jīng)歷中得來的復(fù)雜的知識，而如果英國社會動脈真的不流暢的話，這種知識的有趣就將或多或少地遭到破壞.(尼古拉斯·里曼恩)

Convertible into cash:
可兌換成現(xiàn)金的：
例句：
fluid assets.
流動資產(chǎn)

來源：
From Middle English [flowing]
源自 中古英語 [流動]
from Old French fluide
源自 古法語 fluide
from Latin fluidus
源自 拉丁語 fluidus
from fluere [to flow] * see bhleu-
源自 fluere [流] *參見 bhleu-

【引伸】
fluid.ity
flu.idly
adv.（副詞）