Spursing

Spursing is to fail at something when you have been on track and very close to success. It can be used as a synonym of the slang word bottling, which means the same thing.

He is really spursing his education. He started so good but recently he has had so many bad grades that no University will admit him.

Spursed

It is a slang expression, meaning to come up short, to fail at something or to lose something(at something) after being in a very favorable position to succeed.

My brother completely Spursed his driving test. He was having the perfect drive, with no errors but towards the end he didnt stop on a Stop sign.