The leading theory for the etymology of the “foot” in “football” is because it’s played on foot unlike, say, jousting or polo.

It gets the name from "rugby football" from the time where both rugby and international football ("soccer") were considered related sports and often shared rules and associations (such as the London Football Association, from which Princeton imported rules to the US, and which eventually started to split as the sports split further).

The change in shape from a round ball to the "handegg" eventually derived from the first American innovation in "rugby football" of the forward pass. Even with the forward pass, the game required kicks into goals for a long while with the "touchdown" a further later innovation (though also influenced by reimporting rugby rules, as it relates to the rugby "try"). Kick offs, punts, field goals, and extra point attempts all still vestigially remain from the rugby origins even as most of the play in between them changed drastically.

American Football is called "football" because it evolved from the "football family". It's like using the term "romance language": Spanish and Italian sound very different today, but they both share roots in Latin. They've also both changed a lot since the days when Latin was a living language.

Also:

basketball -> handball

hockey -> stickball

volleyball -> handball

rugby -> handegg

baseball -> stickball

cricket -> stickball

golf -> stickball

Hopefully this will finally appease the football literalists and make things simpler for you all to understand :)

I like the basketball, volleyball, and baseball way where the noun before ball has some leeway but should be clearly identified with an aspect of the sport.

football -> tackleball rugby -> tossball cricket -> paddleball golf -> clubball hockey -> icepuck

Handball’s already taken though.

I find it werid that you keep calling soccer football.