1. A compliment, meaning you have large amounts of
oxygen, therefore having more brainpower.
2. An insult, meaning you have lots of
oxygen in your head, and very little brain.
The big can also be replaced with other
words describing size, such as massive or huge.
Good luck figuring out which.
Def 1: Dude, he just aced the
test. Must have big
oxygen levels.
Def 2:
Wow, you play Fortnite? You have MASSIVE oxygen levels.