ex-基本解释
pref.表示“由…出来，自”之义
ex-词典解释
1. （加在名词前）表示“以前的”，“前任的”
ex- is added to nouns to show that someone or something is no longer the thing referred to by that noun. For example, a woman's ex-husband is no longer her husband.
e.g. ...my ex-wife.
我的前妻
e.g. ...ex-President Reagan.
前任总统里根
