The answer to the crossword question “Ancient Nahuatl speaker” is AZTEC. The Nahuatl language was spoken by the Aztecs, an ancient pre-Columbian civilization that existed in what is now Mexico. The Aztecs were a powerful and sophisticated society that developed complex systems of writing, medicine, agriculture, art, and religion. Their empire was founded in the 14th century and was at its height during the 15th and early 16th centuries. The Aztecs dominated much of Mexico until the arrival of the Spanish in the 16th century, but their legacy lives on in the language, culture, and traditions of modern-day Mexico. Therefore, the answer to the crossword question is Aztec as they were the ancient Nahuatl speakers.