A fat chick. Characteristics include (but are not limited to): prodigious muffin top, thunder-thighs, cankles, back-tits, ass-belly, breasts much too small for large-sized body, and a fat vagina (from which the term is derived). Beef queefers are completely unaware of their body type, as they tend to dress in such a way as to look like 10 pounds of shit stuffed in a 5 pound bag. A beef queefer is usually the token fat friend in a group of normal to attractive females; as such, they are generally cock-blockers when sober but will fuck anything that has something vaguely resembling a penis when intoxicated. Considered highly dangerous; if encountered, keep away from fridge/snacks/penis at all costs.
Friend 1: "Damn dude, that Sarah chick is a fox!"
Friend 2: "It's a no-go dude; that beef queefer Gretchen is with her. She's keeping that shit on lock-down. Sucks, 'cause Erika's pretty hot too..."
Friend 1: "Naw, dude, we can have Randy buy her a few drinks and take the hit for us, right Randy?"
Randy: "God dammit..."