Menstruation is the name of the process: each month the lining of the womb is shed, and blood leaves the body. Textbooks and clinics use this word. Friends more often say period. It is not dirty and not a joke; it is just the formal name.

Menstruation is the name of the processMenstruation是這個過程的名稱 each month the lining of the womb is shed每個月子宮內膜會脫落 and blood leaves the body血液會排出體外 Textbooks and clinics use this word教科書和診所會用這個字 Friends more often say period朋友之間比較常說period It is not dirty and not a joke這不是骯髒的事，也不是玩笑 it is just the formal name只是一個正式的名稱

It is built from menstruum + -ation, after a late Latin word. So the stem is the old “monthly” word, and -ation makes a noun for a process. That is why it feels like a school-and-clinic word.

It is built from menstruum + -ation這個字是由menstruum加上字尾-ation組成的 after a late Latin word源自晚期拉丁文的一個字 So the stem is the old "monthly" word所以字根是古代表示『每月的』那個字 and -ation makes a noun for a process而-ation則把它變成表示一個過程的名詞 That is why it feels like a school-and-clinic word這就是為什麼它給人一種學校和診所用語的感覺

You can count it: a first menstruation, painful menstruation. You can also speak of menstruation as a general fact of life.

You can count it這個字可以當可數名詞用 a first menstruation, painful menstruation像a first menstruation（第一次月經）、painful menstruation（痛經） You can also speak of menstruation as a general fact of life你也可以把menstruation當成一個generally的生命現象來談

Though actually, people stretch it a little: “during menstruation” can mean the whole time of the period, not only the mechanism inside. It does not mean the same as menopause (when periods stop for good, usually later in life). And it is not a word for mood: you can be tired or sore during menstruation, but menstruation itself is the bleeding process.

Though actually不過實際上 people stretch it a little人們會把這個字用得寬鬆一點 "during menstruation" can mean the whole time of the period『during menstruation』可以指整個經期期間 not only the mechanism inside而不只是體內那個生理機制本身 It does not mean the same as menopause (when periods stop for good, usually later in life)它跟menopause（停經，也就是月經永久停止，通常發生在年紀較大時）意思不一樣 And it is not a word for mood而且它不是用來形容情緒的字 you can be tired or sore during menstruation你在menstruation期間可能會累或不舒服 but menstruation itself is the bleeding process但menstruation本身指的是出血這個過程

Cycles wander. The old idea that menstruation is dirty is a social story, not a body fact.

Cycles wander週期本來就會有些浮動 The old idea that menstruation is dirty is a social story, not a body fact認為menstruation很骯髒的舊觀念，是社會建構出來的說法，不是身體上的事實