Merriam-Webster's Word of the Day - regimen

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 >](https://www.merriam-webster.com/dictionary/regimen)

Examples:

"The last step in a great antiaging skin care regimen is, of course, sunscreen." — Alanna Martine Kilkeary, Glamour, 27 Apr. 2026

Did you know?

Being but humble lexicographers, we cannot say whether an apple a day truly keeps the doctor away, but as far as regimens go, one could do a lot worse than snackin' on a McIntosh. Regimen, which usually refers to a system of rules or guidelines—often for living a healthy life or taking a regular dose of exercise—comes ultimately from a Latin verb, regere, meaning "to direct." Regere led in apple-pie order to the English word regimen, first by way of the Latin noun regimen, meaning "steering" or "control," and then via the Medieval Latin regimen, referring to a set of rules. Other regere descendants fell further from the tree, including [correct](https://www.merriam-webster.com/dictionary/correct), [erect](https://www.merriam-webster.com/dictionary/erect), [region](https://www.merriam-webster.com/dictionary/region), [rule](https://www.merriam-webster.com/dictionary/rule), and [surge](https://www.merriam-webster.com/dictionary/surge). Be sure not to confuse regimen with [regiment](https://www.merriam-webster.com/dictionary/regiment), which refers to a military unit, as doing so could upset the apple cart.