Menstrual is the describing word for things that belong to a period: menstrual blood, menstrual pain, menstrual products, the menstrual cycle. The cycle is the whole roughly-monthly pattern — not only the bleeding days, but the build-up and the shedding. When people say menstrual cup or menstrual pad, they mean tools for those days.

Menstrual menstrual is是 the describing word for things that belong to a period用來形容跟月經period有關的東西的形容詞: menstrual bloodmenstrual blood（經血）, menstrual painmenstrual pain（經痛）, menstrual productsmenstrual products（生理用品）, the menstrual cyclethe menstrual cycle（月經週期）。The cycle這個cycle週期 is指的是 the whole roughly-monthly pattern整個大約以一個月為單位的模式 — not only the bleeding days不只是流血的那幾天, but the build-up and the shedding還包括身體累積和剝落的過程。When people say當人們說 menstrual cup or menstrual padmenstrual cup月經杯或menstrual pad衛生棉時, they mean tools for those days指的是那幾天用的工具。

It comes from Latin for “monthly,” from mēnsis, “month.” Older notes also point toward moon, because a month was first a moon’s span.

It它 comes from Latin for "monthly,"源自拉丁文『每月的』 from mēnsis, "month."來自mēnsis，也就是『月』。Older notes also point toward moon比較舊的資料也指出跟moon月亮有關, because a month was first a moon's span因為最早的一個月，就是月亮繞一圈的時間長度。

In everyday English this is a neutral, slightly medical adjective. You will see it on packets and in health class. There was once a noun menstrual as well, meaning the bleeding itself, but that use is old; what students meet now is the describing word.

In everyday English在日常英文裡, this is a neutral, slightly medical adjective這是一個中性、稍微帶點醫學味的形容詞。You will see it你會看到它 on packets and in health class在包裝上和健康教育課上。There was once a noun menstrual as well曾經也有一個名詞menstrual, meaning the bleeding itself意思是經血本身, but that use is old不過那種用法已經過時了; what students meet now is the describing word學生現在會遇到的是形容詞的用法。

Pair it with a noun: menstrual cycle, not “a menstrual.” Though actually, the tidy phrase “twenty-eight-day menstrual cycle” is a sketch, not a rule. Real cycles wander, especially when someone is young, stressed, or playing a lot of sport.

Pair it with a noun要搭配名詞一起用: menstrual cyclemenstrual cycle, not "a menstrual."而不是單獨說『a menstrual』。Though actually不過其實, the tidy phrase "twenty-eight-day menstrual cycle"『twenty-eight-day menstrual cycle28天的月經週期』這種整齊的說法 is a sketch, not a rule只是一個大概的描述，不是規則。Real cycles wander實際的週期會浮動, especially when someone is young, stressed, or playing a lot of sport尤其是在年紀還小、壓力大，或運動量很大的時候。