The current hot women's clothing size in American fashion and Hollywood. Basically, it translates to "There is only skin covering these bones." Size 0s include Calista Flockhart, Lara Flynn Boyle (who used to be quite striking), Jane Leeves, Paual Devicq, Victoria Beckham/Posh Spice, Portia de Rossi (also used to be cute), Cameron Diaz (no wonder she looks so sickly) and Courtney Thorne-Smith.

PS: A size 0 will not naturally have breasts, a period, or much else that indicates she's female. If a size 0 has cleavage, look for the MADE IN TAIWAN stamp.