大学英语：define

　　vt.1、解释，给。。。下定义;2、限定，规定。

　　Work is defined as the product of a force and the distance through which its point of application moves in the direction of the force.

　　功的定义是力和力的着力点沿力的方向移动的距离的乘积。

　　He has defined his position on the issues.

　　他已表明自己在这些问题上的立场。