The act of trying to consume alcohol without detection. Sometimes applies to drinkers under 21, but is more often used to describe an adult who enjoys an alcoholic drink at potentially inappropriate times.
V. To stick one's face into the crack of a voluptuous booty (clothed or not). For optimal butt-snorkeling, the butt should be plump enough to surround the face in an air-tight seal, the way a normal snorkeling mask would. Essentially the booty equivalent of motor boating.
Person 1: "That is the finest ass I've ever seen."
Person 2: "What I wouldn't do to butt-snorkel that beauty!"
When your down eating a chick out (cunnilingus) and she smashes your face into her pussy, the Nose Snorkel will prevent her gunt from smothering your nose, and allow you to breath.