Mega dome 

When the top of his/her forehead is large and the size of a bowling ball.

That mega dome is bigger Han my football

Mega dome by MEMETEAM XD May 29, 2019

mega dome 

1.
v. getting you dick sucked while doing somthing hella cool like eating a sandwitch or playing video games.

Cupcake resived mega dome from buttercup while playing video games.

mega dome by tara June 19, 2006

megadome 

an unusually large head. not common in most areas of the world. Used as a noun or a nickname. e.g. He has a megadome. or Yo, Megadome!

damn, you got that size 8 fitted, you gots a megadome.
yo megadome, get me a drink.

megadome by kurtisjax November 1, 2006