A sexual act which occurs when a man stuffs a woman's vagina full of sand and then proceeds to have intercourse with her. Dusty Pirate's are obviously performed principally in coastal areas, and often include cinnamon lube to heighten the sensation for both parties.

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.