An act which consists of blood or a blood-like substance, oozing from the vaginal orifice and collecting upon a plug of cotton or other absorbent material which was formally inserted into said cavity. And this act, not necessarily requiring a person named Erica, to commence removing the blood saturated plug (tampon) and preceding to illustrate a clown's face on the face of a sexual partner.
That chick I was with last night was on her rag. While I was distracted, she came up from behind and gave me a filthy Erica.
Don't mess with that chic when she's on her rag. She likes to give filthy Ericas.
David: "Dude! I Dirty Sanchezed Amy last night!"
Daniel: "Man, sweet! Da bitch Filthy Erica-ed ME last week!"