2)When a person shits in an exceptionally short amount of time.
DUDE! You just had a power shit!
man that was some power shit you came out of the bathroom in 2 min
A technique developed to save time when doing other more important activities and shitting is neccessery.
Julie was very busy running her company so she had to power shit to save time.
That was a good powershit.
Powershitting saves time.