An acronym used instead of tests/quizzes. It originated in a chemistry class, where test/quizzes were never spoken of and OTDYU was the new hot thing. OTDYU stands for "Opportunity to Demonstrate Your Understanding"
Person 1 : Hey do we have an OTDYU tomorrow?
Person 2 : No it's on Thursday. It's worth 80 points, so you better study!
Person 1 : Oh, thanks!
Bro she told the fat kid in our class "Move! You too big!" I was OTGD!
I was really OTGD when Kanye West took the microphone from Taylor Swift to say Beyonce was better.