I have written about how the German and Spanish words for clock, Uhr and reloj respectively both derive from the Latin horologium with only the r in common. I have now come across a similar example. English wool and Spanish lana are related in the same way, sharing no more than the l.
It goes back to the Proto-Indo-European word for wool, which is h₂u̯l̥h₁náh¶. Goofy has all the details on Bradshaw of the Future . He also explains in simple terms that *wel from the first part became English wool while the suffixed form *welana became Proto-Celtic *wlanā then Welsh gwlân and Latin lana.
Another post on that blog has more about PIE.
¶ It should be all one word but I can’t post it without the spaces after the subscript numerals.