I have a Swinub that I named William. He looked like a William. I also have an Eevee named Frederick, who I think I will make into an Umbreon. Frederick because when I think of Umbreon, I think of the black piggy in Monokuro Boo. I forget why that association exists in my mind. My Typhlosion's name is Fuu because that's the sound that fire makes. : D;; And as soon as I get an Onix, I shall name it Steve. Because all Onix are Steve to me.
All my Pokemon have nicknames (aaaaall of them), but not all of them really mean anything.