If he is fuming, he is smoking — literally. And it is, subtly, the same word in Spanish.
“To fume” comes from the Latin root fumus (“smoke”) from which we also get the common Spanish word for “smoke”, humo. But they don’t sound alike, so how are they related?
The Spanish humo is a great example of the pattern of the Initial F turning into an H in Spanish, alone among the languages of the world. Many Latin words that began with an F, and come to us in English through the Latinate F form, became the equivalent word but with an H- in Spanish. Take hermano and filial, for example. Or fact and hecho.
Other English words from the same root fumus include fumigation (ahhhh!) and the less common fetid. Fetid is a dirty, Shakespearean word, after all.
The English fact comes from the Latin factum, meaning “something that happened.” It is thus an exact cognate to the Spanish hacer, meaning “to make.” How?
The root of both is the Latin facere, meaning “to do.” Fact, and the Latin factum, is just the same word in a different tense.
The Latin facere turned into the Spanish hacer, although they superficially sound different. Their relation becomes obvious once we remember that Latin words that began with an initial f- almost always turned into an initial h- when Latin evolved into Spanish.
Therefore the f-c-r of facere maps exactly to the h-c-r of hacer.
This pattern explains many words such as hierro/ferrari, hervir/fever, huir/fugitive, hoja/foliage!
A “shooting star” in Spanish is an estrella fugaz. Since estrella means “star”, then fugaz is the parallel to “shooting.”
Fugaz comes from the Latin fugere which means, “to run away; flee” — from which we get the English fugitive.
The mapping is obvious with the f-g retained in both versions.
Thus, in Spanish, a shooting star is literally, a fleeing star. But fleeing from what?
The Spanish hilo (cord; thread; string) comes from the Latin for the same, filum. The words sound very different, until we remember that, words in Latin that began with a f- tended to change to h- in Spanish: hijo/filium, and hoja/foliage, for example. Now the hilo/filum make sense!
Interestingly, however, from that same Latin root filum, we get various English words that also quietly show they are descendants of the word for cord or thread. Including:
The Spanish horno, for “oven,” sounds unrelated to any English counterpart.
But it is in fact a close cousin of furnace. Both come from the Latin formus, meaning “warn”.
How did such dissimilar words end up such close cousins?
Because most Latin words that began with an f- followed by a vowel ended up evolving in Spanish (alone among the romantic languages) into an h-. Thus the h-r-n of horno maps almost exactly to the f-r-n of furnace. In both cases, the original -m- evolved into an -n- in the root. But that is a very common transition too, with both sounds being so similar.