yeaup
If the words "yeah" and "yup" met and had a baby..."yeaup" would be the offspring.
Did you spend the night with that chick last night!?
Yeaup!
Yeaup!
yeaup
When you're high or just feeling laid back and lazy, you let out a nice attenuated "yeaup", which is the unison of yea and yup.
"how's it hangin"
"lowww and lazy"
"yeaup"
"lowww and lazy"
"yeaup"