1. An extremely pessimistic person who constantly complains about a problem but does nothing to fix it.
2. Somebody who spends most of their time dicking around on message boards or possibly on urbandictionary.com complaining about all the crappy things in their life.
3. A hilarious comic strip in MAD Magazine about this really pessimistic guy who makes everybody around him miserable.
Emo dude: I'm gonna go online and complain about how much my life sucks because my grades are crappy and I hate my parents and I have no friends!
Regular dude: Get off your ass and do something about it then, bitterman.
A man who has evolved beyond the need for some woman to validate his existence and has a desire for the finer things in life, such as self reliance, marijuana or fine Jamaican rum.
Tom: Chase! Dude, I asked her to marry me and she said yes!
Chase: Yeah, alright. *starts packing a bong*
Tom: Dude, what the heck? I just told you she said yes!
Chase: Yeah, I heard you. Good job on finding a parasite for your weed and freedom.
Tom: Damn, you're such a bitterman...
Chase: Thanks, now can you get the rum out? *lights the bowl*
a fucktard that will drive you anywhere you want if you ask them to.
"drive me to the store bitterman"
"Oh bitterman get my luggage!"
"Fuck you bitterman, but thanks for the ride, you now have to wait outside your girlfriend's house while i do her... then you can give me a lift home"