half bath
The practice of urinating outdoors at a crowded house party so as to avoid the long line for the single indoor bathroom. The half bath can be situated in a garden, yard, driveway or other semi-secluded spot outdoors. Term originates from the name given to the second or guest bathrooms many newer houses are equipped with, but are absent in older houses and apartments.
The line for the bathroom was way too long, so I used the half bath out behind the garage.
bottom-half bath
When one accidently sharts in their pants and enters the shower with only the bottom half naked to clean the buttocks.
"I had to take a bottom-half bath today because I sharted so hard."