When a celebrity loses their prior popularity due to an unpopular expression of an opinion,
Person 1: Man, my friend James used to be so popular, but after he called that guy a faggot, everyone started shit-talking him.
Person 2: Yeah, classic case of the Mel Gibson effect.
The act of being completely smashed and making racist remarks towards Jewish people to authorities in hopes to get away with something you did.
Driver: Aw shit, I'm getting pulled over I can't get another DUI!
Passenger: Going Mel Gibson is a last resort, he may go for it, but try you were in a hurry first
The act of running at someone or something and stabbing it at an upward angle with an object not meant to be a spear.
Movies have a lot of examples of Mel Gibsoning, like originally in the Patriot when Mel Gibson stabbed a red coat with a flag pole