A broad term used to define the various stereotypical antics of the male gender, often of varying degrees of morality. A portmanteau of "man" and "shenanigans".
Hater #1: Is Tom getting blown while playing Madden?
Any act contributing to the misrepresentation of truegender by a transsexual or transvestite for the purpose of attaining sex through trickery.
"With the beer goggles, she looked do-able at the bar, but once we got under those bright streetlights, I could tell by the Adam's apple it was shemanigans."
Short-hand for the word floccinaucinihilipilification, meaning the estimation of something as valueless (encountered mainly as an example of one of the longest words in the English language).