1. To make wise
2. To become wise
He should wisen up to the realities of life.
noun: the rough skin found on the elbow.
Invented as part of an attempt to artificially impose a less phallic etymology on the word wenis. In a bizarre twist, conversely to the urban legend, wisen came from the word wenis.
Nerd: "Your wisen is showing!"
Urchin: "WTF? WENIS."
Teacher: "Detention, young man."
Urchin: "But wenis!"
Teacher: "That's another day without recess. We can keep going if you want."