The ass end of a plane.
Look, Collin, you can see the planus of that 747 from the mall of america!
by avaraxus January 20, 2008
Planus (n): the small circular opening on the rear of an air plane, where the exhaust is released. The anus of the plane.
Check out that planus! It looks old and overused.
by LindsayM April 28, 2009