When the male genitalia (penis) has a slight curve when fully erect. The curve can be dramatic but is often subtle and can curve to the front or either of the sides. These legendary peni are hard to find but do exist and are often more pleasurable.
OMFG that Brazilian dude had a Banana Penis.
by Zombie Mazzy September 29, 2011
When It's curved and yellow..... No not kross's
He has a banana penis.... Oh no poor guy
by Story-Teller January 05, 2015