Mental Five 

When you and a bro high five in your minds because a. You're too far away from each other to actually high five b. You both just can't be bothered to high five or c. Because the action/event was so awesome that a normal high five just wouldn't suffice

Alex: Woah dude that was so cool, mental five

Harry: Nice!

Mental Five by bluedudeinahole September 25, 2014

Mental High Five

In order to save muscular movement and energy, a mental high-five may be performed. To successfully complete a mental high-five, one must count from 3 to 1, then tilt ones head forward slightly (like a head bow) and blink at the same time. Mental high-fives can be performed one to one, or one to a group, which can be incredibly handy when one wishes to high-five everyone in a large group. The saved energy from not having to use your arm can then be used for other more important activities, like sleeping, or playing computer games.

"Dude, that was awesome! Mental high five! 3. 2. 1. Go!"
*Nod and blink*

Mental High Five by mysterio32 September 21, 2011