1.) As a general insult following in the trend of rectal-based phrases, see asshat
2. As a descriptive phrase
1. Dude, he didn't deserve that. You're such an assmar.
2. Don't like it? Sucks to your assmar.
When you can't pronounce asthma, you say assmar
Piggy so fat and can't go up lots of stairs because he's got assmar