When one goes in for a kiss on the lips and is met with a sudden head-jerkmotion by the kissee resulting in lip to cheek contact as opposed to the intended lip to lip. Usually used as a signal meaning, "I am not interested."
Whoa! Sorry, Bro, I saw you goin' for the kiss, but that bitch straight up cheek blocked you! She just wasn't feelin' it.
Verb - To cheek back: "If I tell him to get his own Leap Card he will just cheek me back"
Noun - Cheeker backer: One who cheeks back
Past participle - Chook back: "Here, he just chook me back!"
It is said of the situation where a person has the bad luck to make contact with his testicles against an undefined surface or object, intentioned or not.
Given the nature of the word, it is more appropriate to design cases where the interaction is made with a moving object, for example, a ball.
Although it is extremely painful for the victim, it tends to be considerably funny to people who witness it.
Today in the baseball game the pitcher took a nutshot; the baseball hit him in the nuts.
Man, I just watched the funniest nutshot video ever.