/prɪ'zʌmpʃn; prɪ`zʌmpʃən/
n
1 (a) [U] ~ (of sth) presuming sth to be true or the case 假定; 认定; 假设; 推测
*presumption of her innocence by the court 法庭对她无罪的推定.
(b) [C] thing presumed to be true or very probable 假定属实的事物; 被认定的事物; 极为可能的事物
*The article makes too many false presumptions. 这篇文章中凭空臆测的成分太多.
* We're having the party in the garden on the presumption that it's not going to rain. 我们认为不会下雨, 所以在花园里举行宴会.
2 [U] behaviour that is too bold; arrogance 放肆; 傲慢
*She was infuriated by his presumption in making the travel arrangements without first consulting her. 他事先没和她商量便做好旅行安排, 她对他自作主张很生气.

n
[C]
something that you think is true because it is very likely
presumption that
　the presumption that their wealth is the result of crime
on the presumption that
　On the presumption that the doctor knows best, I took the medicine.
[U and C]law
the act of thinking something is true, bad, or good until it is shown to not be true, bad, or good
presumption of
　the presumption of innocence
presumption against/in favour of
　a strong presumption against development in national parks
[U]formal
behaviour that seems rude and too confident
　She was enraged by his presumption.