1)To represent, in a stereotypical fashion, a memeber of the young, lower middle class black society. Can be used to reference a person of non-balck heritage. Instead of saying something such as "he's a straight up nigga", the phrase would be reduced to a shorter (and more agreeable) "he's straight up"
2) a word use to describe something/ someone that is exciting or worth while
1) "did you see that guy with the ghetto blaster? that guys straight up."
2)- "man, chris. youre badass....you totally chugged that fifth of jack."
"that because im straight up"
-"hey did you go to marks party last week? i heard it was off the chain"
"hell yeah man....that shit was straight up"