To have one large pubic hair protruding from one's zipper, whether purposely or by accident. The term comes from the long barbels, or whiskers that stick out from the mouths of catfish. While the whiskers of catfish house their taste buds and are used to search for food in murky waters, the act of catfishing will only serve to make you look like a complete slob, oblivious airhead, or creepy perv.
"So I was giving a presentation the other day, and I looked down and realized that I was totally catfishing! I was so embarrassed, so I spent the rest of the time with my back to the audience!"
"I was catfishing at the club last night and at least 3 people noticed!"