Daño, Spanish for “damage”, comes from the Latin for the same: damnum. From the same root we get both the English condemn and damn. But what happened to that missing ‘m’?
Interestingly, the Latin m‑n sound tended to turn into a ñ sound in Spanish. This explains how autumn became otoño, for example.
We can still see this pattern preserved in the perfect mapping of d‑ñ in daño to the d‑mn of damn, and the same with condemn.
From the same root we also get the English indemnity, as well as damage itself, although the final ‑n was lost because damage entered English via French.
We can see the parallel but between daño, condemn, damage, and damnum — but how did it come to mean the formerly-vulgar, damn? Think of damn in the old sense of, sentencing someone for a crime they did: you are condemned to hell. A whole slew of English insults come from this same concept, including the word hell itself!