The Spanish Guardar, meaning “to watch over or care for”, and the similar Guardia (the ER! Emergency Room) are both cousins of the English ward and warden. Huh?
Both come from the same Proto-Indo-European root, *wardo, also meaning “to take care of”.
But, as Latin turned into Spanish, the initial W- sound turned into a G- sound but remained the same in English.
Therefore, the Latin-ish G‑R-D maps to the Germanic W‑R-D. Ahhhh!