Origin Saunter

Hello again. Another random thought that came while I was trying to go over my essay. Remember when we read "Walking" by Thoreau and he made up the history of the word saunter? We never figured out where it actually came from. According to Merriam-Webster, saunter may have came from the Middle English word santren, which means to muse. No origin has been proven true, though. Thoreau= a goof.