1. noun
a) A person who is cruel to others, especially those who are weaker or have less power.
b) A hired thug.
2. verb
b) To act aggressively towards.
3. adjective
Very good; excellent.
4. interjection
a) Well done!
Shes finally leaving her abusive husband — bully for her!
b) Used to say that you do not care about someone who has done something nice
Shes finally leaving her abusive husband — bully for her; I dont bleeding care!
Wikipedia foundation.