Someone who uses msn messenger excessively.
Msn faggots typically hang out on msn messenger waiting for someone to sign on. They then assault said person with useless statements, smalltalk, and questions.
Msn faggots usually cannot interact in real life so they use msn only.
People who use AIM, etc. excessively, also qualify as msn fags.
Steve comes home from school everyday, then waits for Kelly to sign on so he can talk to her. Steve is an msn faggot.
I used to talk to people more on msn than in real life. I used to be an msn faggot.