assure

动词 assure:

1. make certain of
   同义词：guarantee, ensure, insure, secure
2. inform positively and with certainty and confidence
   同义词：tell
3. assure somebody of the truth of something with the intention of giving the listener confidence
4. be careful or certain to do something; make certain of something
   同义词：see, check, insure, see to it, ensure, control, ascertain
5. cause to feel sure; give reassurance to
   同义词：reassure
6. make a promise or commitment
   同义词：promise

1. Her success as an actress was now assured.
   她当演员很成功，已毋庸置疑了。
2. We book early to assure ourselves of seats.
   我们及早订票以确保有座。
3. I can assure you that your son will be happy here.
   我可以向你保证，你儿子在这里会很快乐的。

as.sure

v.tr.（及物动词）
as.sured,as.sur.ing,as.sures
To inform positively, as to remove doubt:
向…保证：告知确实如此，以解除怀疑：
例句：
assured us that the train would be on time.
向我们保证火车将会准时到达

To cause to feel sure:
使确信：
例句：
assured her of his devotion.
使她确信他的挚爱

To give confidence to; reassure.
给予信心；使放心
To make certain; ensure:
确实；保证：
例句：
.Nothing in history assures the success of our civilization.(Herbert J. Muller)
.历史上没有任何东西保证我们文明的胜利.(赫伯特J.马勒)

To make safe or secure.
使安全，使稳固
Chiefly British To insure, as against loss.
【多用于英国】 给…保险，以防意外

来源：
Middle English assuren
中古英语 assuren
from Old French assurer
源自 古法语 assurer
from Vulgar Latin *assôcôr3re [to make sure]
源自 俗拉丁语 *assôcôr3re [确认]
Latin ad- [ad-]
拉丁语 ad- [前缀，表.朝，向.]
sôcôrus [secure] * see secure
sôcôrus [安全的] *参见 secure

【引伸】
assur.able
adj.（形容词）
assur.er
n.（名词）
Assure, ensure, and insure all mean .to make secure or certain.. Onlyassure is used with reference to a person in the sense of .to set the mind at rest.:
Assure,ensure 和 insure 都指.使稳固或有把握。. 只是assure 用来指人，有.使某人放心.的意思：
例句：
assured the leader of his loyalty.
使领导确信他的忠诚。

Althoughensure and insure are generally interchangeable, onlyinsure is now widely used in American English in the commercial sense of .to guarantee persons or property against risk..
虽然ensure 和 insure 在一般情况下可以互换， 现在只有insure 广泛用于美国英语中，商业中意指.给人或财产保险以防意外。.