1）define v.定义，define the word解释这个词；be defined by由...；be defined as规定(被称为)
2）Definition n.定义，(物)清晰度。

【例句】
The tree was clearly defined by the light.(show the form or outline of)
这棵树被灯光清楚的描绘了出来。

Boxing has been defined as the art of hit without being hit.
拳击已被定义为没有碰撞的碰撞艺术。