A Wife, Fiancé, or Serious Girlfriend of a U.S. Marine.
A Female Most men find Stunning, Usually a Woman who can have any guy she wants, but remains Completely faithful to her significant other/Spouse while He's away in the Marines Corps.
Guy 1: Damn, Angel Is a total Bombshell!, isn't her boyfriend deployed right now?
Guy 2: Yeah he's in Afghanistan
Guy 1: I Will Totally hook up with her.
Guy 2: Forget it she's a Sem Fi Femme.