When a person is single-mindedly devoted to athletic performance, enjoys suffering through horrendous workouts, and never quits.
See that guy doing 150 barbell thrusters at 135lbs, for time? What a Meatbeast!
by Alpha_SaSQUATch July 20, 2010
A girl with insatiable hunger for the man meat.
Man, that meatbeast loves her bathroom parties.
by The Lizardardo October 07, 2008