A girl who is buttaz but spreadable, in that although she is facially unattractive (buttaz), she makes up for it with a body so good you want to fuck her (spreadable) despite her face. The term Anchor Chick referring to "Anchor's" spreadable range of the everyday dairy product (Anchor's spreadable butter).
Kane: What about her?
Karl: Nah shes ugly.
Kane: Well I'd fuck her.
Kane: Yeah, she's an Anchor Chick.
Karl: What's an Anchor Chick?
Kane: Ya'know, she's butters, but spreadable.