To prove something that is largely believed to be true to be false. Derived from the TV show Mythbusters
"We thought that the show was on Tuesday, but Derek mythbusted and told us it was on Friday."
"Quit mythbusting, Tim. Let us believe what we want to."
One who defies the myth that the entire scrotum, and penis can fit into the vagina at the same time.
"Hey I heard Tom totally myth-busted Anna last night, he got everything in there!"
"My scrotum and penis got lost, I was looking and I found it all inside her Vagina! I thought it wasn't possible, I guess I busted that myth."