define sth (as sth)（词语）的含义；给（词语）下定义；
definev.解释(词语)的含义；给(词语)下定义；阐明；明确；界定；画出…的线条；描
The powers of the police must be clearly defined.
警察的职权必须明确界定。
It is difficult to define the border between love and friendship.
爱情和友情之间的界线难以划清。
These categories are not well defined.
这些类别划分得不太明确。
