1 [I,T] decide (to do sth);decide against (doing) sth;decide about/on sth;decide that... to think about two or more possibilities and choose one of them 选定；决定: There are so many to choose from -- I can't decide! 有这么多选择，我拿不定主意！We've decided not to invite Isabel. 我们决定不邀请伊萨贝尔。She decided against borrowing the money. 她决定不借这笔钱。They decided on a name for the baby. 他们为婴孩选定了名字。He decided that it was too late to go. 太晚了，他决定不去了。The date hasn't been decided yet. 日期还没有定好。

2 [T] to influence sth so that it produces a particular result 起决定作用；决定（结果）: Your votes will decide the winner. 你们投的票将决定谁是优胜者。

3 [T] to cause sb to make a decision 使（某人）作决定: What finally decided you to leave? 最终是什么使你决定离开？ ☞noun decision, adjective decisive 名词为decision，形容词为decisive