When someone is exaggerating/faking their high to make other people think they are higher than they really are.
This often happens when you're around someone who wants to be liked by everyone and fit in.
Often people will be known has a "ridder"
It's the moments when you are high on anything and a person just does something that makes you think "Wow shes/hes faking it"
Bob "Dude, last night Alex and I were hanging out and he was riddin to make me think hes cool."
Tom "Yeah Alex is a ridder, I have smoked with him a couple times. He just wants to fit in. He hears stories about people getting high and he tries to do the things he heard in the story to make people think hes really high."