The Spanish vínculo (which we’ve previously discussed) comes from the Latin vincere — “to conquer.” (We previously reviewed the Proto-Indo-European root, which gave us the Latin word; the Latin is the intermediary word between the PIE and the English!).
From that same root, we also get.… province (along with the prefix pro-, “before.”)
But how did “conquer” evolve into these words? Province is easy: a province is literally, land you’ve conquered!
And that helps explain vínculo: somewhere you conquer, you make a deep connection with that place. Even turning it into a province.
We can clearly see the v‑n-c root in both words.