"Sa duh" is a term used typically by white male teens when talking to other male teens. They have changed "Sup Dude" to an even shorter and more obnoxious version. Typically this phrase is said at every moment one white male teen encounters another.

A person, place or thing that is extra.

Way of saying something is obvious.

obvious; no kidding, sherlock!, or are you kidding me?

Duh

Duh

When "The Chick " on meebo says duh, it means you're dumb.