Don't care; Shut up; You're lame
Mebs is a word you say to someone after they say something that is either lame, not funny, or just plain stupid. You can also Mebs someone if they just look lame or goofy. Also if someone says something in attempt to fish for compliments, you immediately Mebs them.
"I am so depressed, no one likes me. I wish I had friends."
"Mebs to your emo ass statement."