To avoid a fun or risky activity in order to get some extra studying done.
dude a: "bro, we're gonna base-jump off the Brooklyn bridge and then shark-dive with white killers! are you in??? "
dude b: "sorry brother, I think i'm gonna NERD OUT today. I have a midterm exam tomorrow".
to play video games on a pc or video game console
i am going to go nerd out for a bit.