Wood Ninja 

A guy who very gracefully tries to grab another guys dong. Usually because he has hidden homosexual feelings, but sometimes just because he is a dumbass.

Eric is such a wood ninja.

Wood Ninja by ElectricBananaMan September 2, 2009

Ninja wood 

The unexpected,unprovoked erection that occurs while in public. Usually characterized as coming out of no where, particularly in the morning (at work or in class)

Scholars maintain that it a
reverberation of morning wood...
similar to an after-shock associated
with earthquakes

Morning wood is to ninja wood as
Earthquake is to after-shock.

This morning, in my math class, I had a mean case of ninja wood that came out of nowhere. (It snuck up on me like a stealthy ninja)

Ninja wood by Chris A. P. February 9, 2007