noun. a vein, as of a leaf or the wing of an insect.
Simon was a weird guy with an even weirder sense of humor. And he loved to play with himself. Loved it. It wasn't a sexual thing. No. It was an art he called genital origami. He'd spend hours working on his so-called "dick tricks." The Hamburger. The Pelican. The Flying Squirrel. His favorite was a trick he called The Windsurfer. He'd stretch his scrotum flat and tight so that it looked like a sail. His girlfriend laughed at him, but thought he should call it The Butterfly. When he placed a flashlight against the underside of his flattened sack, the silhouetted nervures looked like a Monarch Butterfly wing.