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 an f- tended to change to h- in Spanish: hijo/filium, and hoja/foliage, for example. Now the hilo/filum makes 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:
- File (as a verb; to file your nails or papers) — what is filing if not using a thread to shorten or separate different items?
- Profile — With the Latin root pro- (put forth!), what is profiling it not drawing out or dragging out information about someone?