Can be of male or
female gender.
One who thinks he/she is super great and attractive and must be idolized. Very selfish. Their head is so humongous that it cannot fit through a doorway. Comes on suddenly. Usually induced by alcohol. Includes a jumbo full teeth smile that is very phony. Lives a lifestyle which includes champagne wishes and caviar dreams on a beer budget. Always overshadows their mate. Is often seen as a
family trait.
Can also be a verb: jackheadness