Individual, usually male, who will drink coffee, energy drinks, or soda in great excess and/or every chance he or she has. Motivation for such actions could be chemical dependency on caffeine, or the desire to seem "hard-core" by being seen drinking energy drinks.
John: Jeez, my brother drinks like two 12-packs of soda in one sitting.
Jake: What a freaking caffiend.
James: Why is Jason always carrying a can of Monster to class?
Derek: 'Cuz he's a caffeind, dude.