Top definition
The penis identity is a mathematical equation, or identity: 8=D. The identity is similar to others, such as Euler's identity, in that it uses constants rather than variables. It is occasionally written with multiple "=" for emphasis.
Instead of writing down formulas on my chemistry cheat sheet, I just wrote the penis identity: 8=====D.
by Jario777 February 03, 2011
Get the mug
Get a penis identity mug for your cat Jerry.