An Anglo-French chess announcement became Middle English chekmat and modern checkmate.
The Persian analysis behind mat is preferred but qualified in the source.
Sources
- Merriam-Webster: checkmate
The noun derives from the announcement; the deeper mat analysis has a caveat.
- University of Michigan historical dictionaries · MED7422
Meanings of the older forms on the word path.
- Online Etymology Dictionary · checkmate
Meanings of the older forms on the word path.