A song in a musical in which the singers are all male and the song is of a high manful quality; usually involves singing about objectifying women and/or fighting.
Following his fifth keg of beer, Kevin ripped the horn off of his pet narwhal, and then nailed his porn-star girlfriend for hours. Subsequently, he felt mantastic.
Wickedly awesome. Like that girl from high school that everyone got along with. Or your really good female friend who's been to hell and back with you and still can make you feel good with a compliment when you need it and/or a kick in the ass when you deserve it. Awesome person who'll rock your world.