regimen

noun

reg·​i·​men ˈre-jə-mən 

also

ˈre-zhə- 

1

a

: a systematic plan (as of diet, therapy, or medication) especially when designed to improve and maintain the health of a patient

b

: a regular course of action and especially of strenuous training

the daily regimen of athletes

2

: government, rule

3

: regime sense 2c

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, erect, region, rule, and surge. Be sure not to confuse regimen with another of its kin, regiment, which refers to a military unit, as doing so could upset the apple cart.

Synonyms of regimen

• government
• administration
• rule
• regime
• governance

Examples of regimen in a Sentence

with the start of the new year, a new party will have regimen over the nation and, hopefully, bring some much-needed change

Recent Examples on the Web

The combination regimen met the main study goal of significantly extending the time patients lived without their melanoma returning, compared with Keytruda alone. — Annika Kim Constantino, CNBC, 19 Aug. 2026

The combination treatment regimen pairs the personalized vaccine with Merck's Keytruda, which had previously been used to treat the cancer alone. — Sony Salzman, ABC News, 19 Aug. 2026

But once the regimen begins to crowd out the rest of a person’s life, the obsession can do real harm. — John Vorwald, Robb Report, 16 Aug. 2026

Peters has been open about his substance use, arguing that his particular pharmaceutical regimen enhances his productivity and cognitive capabilities. — Brady Brickner-Wood, New Yorker, 12 Aug. 2026

Word History

Etymology

Middle English, from Medieval Latin regimin-, regimen position of authority, direction, set of rules, from Latin, steering, control, from regere to direct

First Known Use

14th century, in the meaning defined at sense 1a

Kids Definition

regimen

noun

reg·​i·​men ˈrej-ə-mən 

-ˌmen

1

: a regular course of treatment

2

: a form of government : rule

Medical Definition

regimen

noun

reg·​i·​men

ˈrej-ə-mən also ˈrezh-ə-

: a systematic plan (as of diet, therapy, or medication) especially when designed to improve and maintain the health of a patient