Etymologically

In Russian, the words for "caress, endearment" and "least weasel" are homonymous and possibly related etymologically.

Etymologically, checkmate means "the king is dead". However, the king has not "died" in the game of chess for a long time. In fact, the king is the only piece that cannot even be captured, although checkmate finishes the game and, strictly speaking, can be considered as a "death" for the king.

Rivalry means, etymologically, a dispute between landowners because Roman properties were often separated by a river ("rivus" in Latin).

The Greeks and Romans referred to everyone else as "barbarians" -- etymologically those who only babble, only go "bar-bar."

The German language, as far as I know, is the only one in the world in which the words for debt and guilt are etymologically the same — the word for debt is “Schulden,” and for guilt it’s “Schuld.”