An Andrea's vagina hole that resembles a "Full Moon". Size and all.
"Dude, I boned Andrea the other night! Even after a kid, I didn't expect her to have a Full-Moon Poon like that!"
Pussy that can be seen when a girl has mooned you
Guy1:Did you see the ass on that girl that just mooned us?
Guy2:Naw man I was too busy starring at that moonpoon