The word fail comes to us through Middle English failen, through Anglo-Norman failir, from the Old French word falir, which meant "to make a mistake". This is not too big of a change from today, but is important as we trace the term further to Latin fallere, which meant "to trip", since tripping is a mistake. Earlier, that meant "to cause to fall", and it's from the Proto-Indo-European root bhal, "to deceive". This makes sense as deception can also lead to tripping, which causes falls. All right, rewind for a second. You might have noticed that fallere sounds the word "fall" and also means "fall". Is there a connection? Nope! Fall, through Old English feallan and Proto-Germanic fallana, traces to a Proto-Indo-European root sounding like pol and actually meaning "fall" for real this time (also the root of the synonym for "autumn"). Not a fail.
Adam Aleksic, a leading contender for valedictorian of his high school, is a 215-month-old boy with disturbing interests in etymology, vexillology, geography, and law. Adam would like to one day visit Tajikistan and probably isn't spying for the Uzbek government.
The Etymology Nerd