1 [C] something that you accept is true even though you have no proof 假定；假设: We'll work on the assumption that guests will be hungry when they arrive. 假定客人到来时肚子饿了，我们将据此行事。It's unfair to make assumptions about a person's character before you know them. 在认识之前就臆断一个人的性格，这是不公正的。a reasonable/ false assumption 合理的／错误的假设

2 [U] the assumption of sth the act of taking power or of starting an important job 掌权；就任要职