When an object (usually of desire) is too much to be handled to be simple described as gigantic or humongous; what x-large is to large, gigongous is to xxx-large; what j-lo's booty is to william hung's face; more of an active expressive adjective than ginormous or gimongous.
Everytime the camel takes a step, the lady's boobs slap her own face. Why is that?
Because ... they are gigongous!!!