“Shat mat” is an Arabic expression that means “the king is dead,” and it’s the origin of the term checkmate. The game of chess existed in the East in many different forms since the sixth century, it reached Europe via the Arab world. The term “mate” in the word “checkmate” has nothing to do with the English word that means friend or companion. 

Instead, its true meaning is more closely related to the modern Persian word “mate,” which means “unresponsive” or “unable to respond.”