look up any word, like blumpkin:
 
1.
To overtly use proper grammar, really long sentences, and pompishness in day to day life.
Brian: "Hey dude let's smoke a blunt"

Onder: "I do think that is such a terrible idea, and thus, we should not do such a thing. But should you wish to do so, you do understand that you would be breaking the law and have a chance of being imprisoned? I beseech you to not smoke such cannabis in my face"

Brian: "wtf dude why are you so onder?"

Onder: "I am deeply offended at your usage of such profane language. Please abstain from asking me with such brash and terrible manner."
by 1010102 April 19, 2010
 
2.
To pull an Önder(pronounced as under).
Used to indicate a very stupid move of accidentally hitting an USB memory key while it is still in the USB sloth off the computer, thus snapping it in 2 or more pieces.
To pull an Önder on someone.
He pulled a Önder on me!
Don't you dare to pull an Önder on me!
by David I June 06, 2007