A person (typically male) who is jealous and/or envious of anyone with some sort of an advantage over him. He will proceed to tear down and/or belittle those with said advantage to make himself feel better.
person 1: WOOT! I just got into Yale!
person 2: Pffft! Your mommy and daddy probably pulled strings to get you in! You'll probably flunk out after a semester 'cuz your SAT scores were nothing but luck! Yale is so overrated anyway! Everyone knows that community college is way better!
person 1: You're such a jealous jerry! I'm not going to let you drag me down! Someday I'll be driving a Ferrari and dating a supermodel! I don't need the negativity of people like you in my life!