Also, a ball that isn't round is still a ball. Not an egg.
Ehhh, gonna have to disagree with you on that one. Several reasons:
- Hand someone an egg, and have them describe the shape. I bet you they will not say "it's shaped like a ball".
- I think if you asked people to list key aspects of balls, they will say "spherical" and "it rolls". Neither apply to the inflated egg.
I think it's just the same as with the "foot" part. Historically it *was* a ball indeed, but it changed shape to no longer really be a ball, but it's just continued to be called that way. I mean, it's the same with skeet shooting, where the objects still are called "pigeons". Can a disk-shaped object thus be a pigeon? Not really. It's just that because of history, people continue to use the term.