名詞 constraint:

1. the state of being physically constrained
   同義詞：restraint
2. a device that retards something's motion
   同義詞：restraint
3. the act of constraining; the threat or use of force to control the thoughts or behavior of others

1. Soon tired of the constraint of military life.
   很快厭倦了軍事生活的約束
2. Not in confinement or under constraint; free.
   自由不受約束的或不受限制的; 自由的

con.straint

n.（名詞）
The threat or use of force to prevent, restrict, or dictate the action or thought of others.
強(qiáng)制：使用或威脅使用強(qiáng)制力量來阻攔、限制或命令他人的行動或思想
The state of being restricted or confined within prescribed bounds:
被約束：被限制或約束在規(guī)定范圍之內(nèi)的狀態(tài)：
例句：
soon tired of the constraint of military life.
很快厭倦了軍事生活的約束

One that restricts, limits, or regulates; a check:
約束：約束、限制或制約性的事物；抑制物：
例句：
ignored all moral constraints in his pursuit of success.
在他追求成功的過程中忽略了一切道德約束

Embarrassed reserve or reticence; awkwardness:
拘束：局促不安的拘謹(jǐn)或沉默；窘迫：
例句：
.All constraint had vanished between the two, and they began to talk.(Edith Wharton)
.兩人之間的拘束感都消失了，他們開始交談起來.(伊迪絲·華頓)

來源：
Middle English constreinte
中古英語 constreinte
from Old French [from feminine past participle of] constraindre * see constrain
源自 古法語 [] 源自constraindre的陰性過去分詞 *參見 constrain