1. The woman who gave birth to you and/or raised you.
2. An all-purpose insult, used to end a conversation, cover for the fact that you can't think of a witty comeback, or pwn somebody. When used in this sense, the implication is that your mom is sexually promiscuous, of below-average intelligence, grossly overweight, or any combination thereof. Does not necessarily have to make a lot of sense, e.g. 'Your mom goes to college!'
3. A ho.
Dick: '...therefore, your argument can be proven irrefutably incorrect.'
Jane: 'Your mom!'
Dick: 'Where's the remote control?'
Jane: 'I left it in your mom.'
Stephen Hawking: 'The whole history of science has been the gradual realization that events do not happen in an arbitrary manner, but that they reflect a certain underlying order.'
Dick and Jane: 'Your mom doesn't happen in an arbitrary manner!'
Using your mom (or the mom of a friend) as your "wingman" to pick up a girl at the bar. It works because you seem nice for taking a mom out to show her a nice time and your intentions could be nothing but good.
Joe: Hey did you bring a girl home last night I thought you were hanging out with your friend's mom while she was in town?
Phillip: Yeah, we went to a bar downtown and she was a fantastic wing-mom. The girl I was talking to thought it was sweet that I was showing my friend's mom around town.
A parent, who is assumed to be female, that is in need of constant arguing or yelling. It has been said that they are never wrong, and can give a 30 minute phone lecture on posting their name on the internet. They usually have miserable children who hate them.
Dude1-"homie i gotta be home from the party at 9 because my moms a bitch."
Dude2-"Fuck why do you have such a Jew Mom?"
Dude1-"I don't know, lets pack another bowl"