The Spanish hembra, for “female” (usually in regards to animals) sounds nothing like the English feminine. But it turns out that they are etymologically identical.
Both come from the Latin for female, feminina. Hembra sounds so different because the f-m-n root is changed to h-mbr via two different patterns:
These two, taken together, show a clear mapping of f-m-n to h-mbr.
Here’s the interesting part: the m-n sound in Latin consistently changed into the -mbr- sound in Spanish. Thus, we have parallels like nombre and nominal. And hombre maps exactly to this pattern with both ad hominem and hominid.
The usual Spanish word for “name”, nombre, is very closely related to the English word nominal, in an interesting way. Not only does nominally mean “relating to the name”, but there is an interesting etymological pattern between the words.
Latin words with an m-n sound usually turned the m-n into an mbr sound as Latin evolved into Spanish. Thus, we see curious patterns like hominem becoming hombre, and famine and hambre being closely linked.
The same pattern applies here. The Latin nominalis turned into the Spanish nombre and the English nominal — thus the n-m-n of nominal maps exactly to the n-mbr of nombre!
We see the same pattern here. Both alumbrar and illuminate come from the Latin luminare, meaning the same, “to light up” — from which we also get the English luminary.
Thus, the l-m-n in the original corresponds to the ll-m-n in the English illuminate and the l-m-b-r in the Spanish alumbrar.
Firstly, the initial f-to-h pattern: words that began with an f- then a vowel in Latin tended to have the f- turned into an h- when Spanish evolved into Latin. Huir and Fugitive is another example of that pattern.
Secondly, the mn-to-mbr pattern: when the letters in Latin “m” and “n” appear together, often separated by a vowel, they usually became “mbr” as a unit in Spanish.
Thus the f-m-n of famine maps directly to the h-m-b-r of hambre.