What your wife, girlfriend or fiance turns into during a visit from aunt flow. Very similar to a monster, but the transformation is periodic (pun intended).
John: "Hey Joe, once a month I feel like I'm married to Bela Lugosi."

Joe: "Right there with you bro. Once a month my Ruby turns into the Wolfman, Dracula and Fankenstein all rolled in one terrible menster."
by BigBlackBlick May 21, 2010
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