In Britain, it has the meaning of being truthful, honest :
"I won't hurt you - straight up I won't."
In America, it has been further adapted:
get straight to the point. No BS, I am telling you exactly what I mean;
So 'that's straight up garbage' is not mincing words, he's saying exactly what he means; or 'that's absolute garbage'.
Anyone refine this?
Student or Learner