The story
- Proto-Indo-European*ped-
- Proto-Indo-European*pṓds
- Proto-Germanic*fōts
- Proto-West Germanic*fōt
- Old Englishfōt
- Middle Englishfot
- Proto-Indo-European*bʰel-
- Proto-Germanic*balluz
- Old English*beall
- Middle Englishbal
- Middle Englishfotbal
- English todayfootball
From Middle English fotbal, footbal, equivalent to foot + ball, because the ball was primarily manipulated with the feet in early versions of the game (though some modern varieties involve more handling than kicking). The name for the briefcase is a play on “dropkick”, the code name of an early version of the nuclear war plan.
Etymology from Wiktionary, CC BY-SA 4.0.