While fucking a skank in the ass, you strike a solid turd plug. Upon discovering this buried treasure deep in her booty, you scream, "ARRRRGHHH!", like a pirate.
Last night sucked, man. I was ass-fucking your sister and hit Pirate's Treasure. That girl needs to eat more greens.
Noun. A female who travels with a large group of men, servicing each one of them in turn to placate the crowd. This term was created in honor of the brave women who traveled with pirate ships on long journeys, keeping them sane and satiated.
You: I'm going to hang out with the ENTIRE football team tonight!
Me: Pirate Hooker.
You: I take offense to that.
Me: Shut up hooker. Be proud of your heritage.