Sentence:  “Did you know your <WSD>wenis</WSD> is showing?” “My what?” “Your <WSD>wenis</WSD>!” How hilarious. This joke — which I didn't get — was on me. “You got punk'd, girlfriend!” squealed Caitlin when I told her. Kitch had heard that one before. “<WSD>Wenis</WSD> is the medical term for the flabby skin on the elbow,” he said. I stood in front of the mirror, fingering my <WSD>wenis</WSD>. Flabby, was it? 
Meaning of the word marked with <WSD> tags:  The skin on the outside of one's elbow.