1) They call them spiders, but what do they spide? I originally asked this here, funny answers...
2) They are called fingers, but what so they fing?
3) What exactly do hammers ham?
4) When's the last time you've seen a grocer groce?
Update: This link wasn't the inspiration of my quick article, but something funny I found soon after: Do fingers fing? And then Urban Dictionary has a say: fing (nsfw).