Means that you will never be better than what you are now. Comes from the movie 'Drum Line' when Nick Cannon was running up the steps and he fell and his band coordinator told him "Boy, you gonna graduate in that white T-shirt. Damn!"
Yo, this is my 3rd year in Geometry. I can't pass it for shit.
A jumpoff. Just another way of secretly expressing someone is a slut if the person is nearby so words like jumpoff or hoe is too obvious. It comes from the 10th letter of the alphabet and the 15th alphabet: 10=J and 15=O which translates to J.O. which is short for jumpoff