It might seem obvious in retrospect but it wasn’t at the time. Vulva (yes, that word!) and the Spanish for “to return”, volver, all come from the same root: the Latin volvere also meaning “to return.” Yes, the words are almost identical and the v‑l-v in both maps exactly to the other. It should have been glaringly obvious, I just never realized it! The vulva, after all, does roll back and forth! (Sorry, I couldn’t resist the comment!).
Lots of other super-interesting words come from the same root: valve, etc. Over the next weeks we’ll post them too! Volver is a particularly rich root; people have been going back and forth since time immemorial!