The opposite of a Nathan. (See Nathan Definition) Like a Nathan's evil twin brother, trying to hide himself behind the glorious ways of a Nathan. A Nathyn will use his name's illusion to break hearts, and fool women into think he has a huge penis, and a caring heart, like a Nathan. Their main weakness is there avoidance of showing their name, or writing it down, in a situation where their true, evil side will show through. Truly the bane of mankind, they also like to snack on babies.
Girl 1: "Hi! I'm Ashleigh!"
Nathyn: "Hey, I'm Nathan, I have a huge penis, and I'm really nice!" *eats a baby*
Girl 1: "Oh that's really cool!"