Merriam-Webster's Word of the Day for October 6, 2026 is:regimen \REJ-uh-mun\ noun Regimen refers to a plan or set of rules about food, exercise, etc., designed to make someone become or stay healthy. // Sherry’s personal trainer started her on a workout regimen of 30 minutes on the treadmill followed by 30 minutes of weight training. See the entry > Examples: "The last step in a great antiaging skin care regimen is, of course,