An action of drinking any sort of digestible liquid. This may be water, soda, coffee, juice, ect. Usually when one asks if they may "take a sip" of said liquid, but they instead decide to drink much more than they asked for.
This is a "glug."
I offered Ian a sip of my Snapple.. he proceeded to glug my tasty drink. I proceeded to slap him.
To describe something or someone as being totally emo, or metalcore. Generally kids with white belts, bad haircuts, and terrible bands are described as glug
God damn, that dude with the Panic! At The Disco t-shirt at last call was totally glug.