Weck

To fail a manual or nose manual in skateboarding by scraping your tail or nose (respectively) on the ground.
also used as a general term for not doing a skateboarding trick properly. E.G. not grabbing tuck-knee on an indy grab, or putting your hands on the wall while executing a wallride

That wasn't a make, man, you wecked the hell out of that manual!

tuck knee

The "proper" way to do an indy grab in skateboarding.
involves tucking your back knee into the nestle of your front leg, and reaching your arm over your back leg to grab the board, as opposed to grabbing inbetween, which may result in a "stink bug" pose

you have to learn to frontside air proper! you never heard about the tuck knee?