A phrase used in the popular tv show "30 rock" where cast member Liz Lemon ( Tina fey ) gives herself props by putting her hands up in the air, shaking them, and saying, "I'm high-fiving a million angels!"
A person who thinks they are awesome, and acts like they are the best/have the best tastes, even though they are way passed their prime. The name is relevant because they tend to 'Hi Five' after almost every positive event.
Similar to a Bro because of their tendencies to wear nothing but name brand clothing, and they're 'Party Life' attitude.
Made known by the Local H song 'Hi Fivin MF'
Mid 30's guy: "Dude, this concert is killer! WOO! FREE BIRD!"