Note: This is an excerpt from my forthcoming book Words from Hell: Unearthing the darkest secrets of English etymology (Chambers, 2023).
The word “sabotage” is derived from the French word saboter, which originally meant “to clumsily bungle something,” but carried the literal meaning “to walk noisily.” The base word sabot arose in the 13th century as a word for a wooden shoe, and it in turn is a variation of the older savate, meaning “old shoe.”
There’s a common folk etymology claim suggesting that “sabotage” first appeared in the French and English industrial revolutions and referred to the idea that during labor disputes workers would throw shoes into machinery as a form of rebellion.
Sabotage was indeed associated with labor strikers in both French and English—and it’s possible that workers did chuck shoes into machinery to stick it to the man. It even seems that the idea of throwing shoes into machinery was symbolically associated with workplace rebellion.
But the word “sabotage” is not derived from this act because it is recorded with other meanings before it was ever associated with workers.
The earlier meaning is just messing up or bungling something clumsily or unintentionally—like playing music badly, for example. So the initial sense may have been something like tripping over your own feet, or just generally not being very nimble and graceful, as though you’re clomping about in wooden shoes.
It was extended to workers later. Even then, the meaning of “sabotage” was mostly general: Sabotage referred to doing your work badly and pretending it was unintentional, thereby causing problems for your employer without getting fired.
Useless Etymology 