/dɪˈfaɪn ||; dɪˈfaɪn/verb[T] 1 to say exactly what a word or idea means 精确地解释；下定义: How would you define ‘happiness’? 你怎样为“幸福”下定义？
2 to explain the exact nature of sth clearly 清楚说明；阐明: We need to define the problem before we can attempt to solve it. 我们先要界定问题才能试图解决它。