What is a bully?

bully
n.[C]
1. 恃強欺弱者;惡霸
He is a bully with a coward's heart.
他是個色厲內荏的傢伙。
2. 【古】為妓女拉客者,拉皮條者
vt.
1. 威嚇,脅迫;欺侮[(+into/out of)]
The new boy was constantly bullied at school.
新來的男孩在校老是被人欺侮。
vi.
1. 欺侮人;橫行霸道
a.
1. 【口】特好的,第一流的
What a bully idea!
多妙的主意!
2. 霸道的;像流氓的
ad.
1. 很,極;突出地
I like swimming bully well.
我非常喜歡游泳。
int.
1. 【口】好,妙
Bully for us!
好啊!

bully means some1 who always pick on somebody else. For example: student 1 always ask student 2 for money, otherwise he will kick his ass. in this situation, student 1 is a bully