look up any word, like pussy:
 
1.
A sudden and loud burst of laughter. Sometimes associated with an evil accomplishment or with the destruction of something OR someone.
(Unusually funny text message recieved) "Bwa ha ha ha" or "I'm going to take over the world. Bwa ha ha ha" OR "I will destroy them. Bwa ha ha ha"
by moxielady321 March 17, 2011
 
2.
Improper use of the much maligned correct Muahahaha. Often used with much gusto in place of actual intelligence.

Please see Muahahaha.
I ate the eggs....Bwahahaha
by Colin April 09, 2004
 
3.
A term used by a twat in usenet. Meant to mean "ha ha". Proponents generally ignorant of fact that no-one starts laughing with a "b".

Considered by those with a slim grasp of the English language to be the last word in witty discussion.

Actual occasions when user has laughed whilst typing it: zero.

An indication of the twattiness of the user can be discerned by the levels of:

(a) CAPITALIZATION
(b) hahaha's following 'bwa'
(c) exclamation marks following word
You are more l33t than me?

Bwahahaha!
by Banana Republic July 29, 2003