define /diˈfain/ vt. 1.下定义，释义：define man as rational animal 把人定义为有理性的动物 A dictionary defines words. 词典解释单词。2.规定，确定： define the boundary between the two countries 确定两国边界The Constitution defines the powers of the president. 宪法规定了总统的权利。参见definition