TwiHeart refers to a person who is unconditionally and irrevocably obsessed and in love with the Twilight Saga. This includes books and movies: Twilight, New Moon, Eclipse and Breaking Dawn. A Twiheart has read every book and seen the movies more than a dozen and a half times. A Twiheart also loves the Twilight Actors as much as they love the Characters themselves :) and yes the TwiHearts LOVE Twilight memorabilia!
That girls wearing a Team Edward shirt, you know shes a TwiHeart.