menstruation

noun

men·​stru·​a·​tion ˌmen(t)-strü-ˈwā-shən 

men-ˈstrā-

: a cyclical discharging of blood, secretions, and tissue debris from the uterus that recurs in nonpregnant breeding-age primate females at approximately monthly intervals and that is considered to represent a readjustment of the uterus to the nonpregnant state following proliferative changes accompanying the preceding ovulation

also : period sense 6c

Synonyms

• monthlies
• period

Examples of menstruation in a Sentence

a first menstruation can be somewhat scary for girls who are unprepared

Recent Examples on the Web

It is worn for three weeks per month, with one patch-free week during menstruation. —Lindsay Curtis, Verywell Health, 15 Jan. 2025

Prostaglandins cause uterine contractions during menstruation, which helps shed your uterine lining and can cause cramps. —Chantelle Lee, TIME, 15 Jan. 2025

Related article Kids are starting menstruation earlier, study shows. —Dr. Jamin Brahmbhatt, CNN, 3 Dec. 2024

The cycle begins on the first day of menstruation, with menstrual bleeding usually lasting about five to seven days. —Anna Giorgi, Verywell Health, 4 Jan. 2025

Word History

First Known Use

1686, in the meaning defined above

Kids Definition

menstruation

noun

men·​stru·​a·​tion ˌmen(t)-strə-ˈwā-shən 

men-ˈstrā-shən

: a discharging of blood, secretions, and tissue debris from the uterus at periods of approximately one month in female primates of breeding age that are not pregnant

also : period sense 3c

Medical Definition

menstruation

noun

men·​stru·​a·​tion ˌmen(t)-strə-ˈwā-shən, men-ˈstrā- 

: a discharging of blood, secretions, and tissue debris from the uterus that recurs in nonpregnant human and other primate females of breeding age at approximately monthly intervals and that is considered to represent a readjustment of the uterus to the nonpregnant state following proliferative changes accompanying the preceding ovulation

also : period sense 1b