The vagina is a part of a woman's body: the tube inside her that goes from the outside opening up to the uterus (the place where a baby grows). It is a real body part with a real name, and doctors, nurses, health books and school biology classes all use this word plainly.

the vaginavagina（陰道） is a part of a woman's body是女性身體的一個部位：the tube inside her that goes from the outside opening up to the uterus是從外面的開口一路通到子宮的一條管道（the place where a baby grows也就是寶寶生長的地方）。it is a real body part with a real name它是一個真正的身體部位，有一個正式的名字，and doctors, nurses, health books and school biology classes all use this word plainly醫生、護理師、健康書籍和學校的生物課都會很自然地用這個字。

It is not a rude word, but it is a private word — in normal daily talk people do not say it unless there is a reason, like talking to a doctor, reading about health, or teaching a child the names of body parts. Say it calmly, the same way you would say 'stomach' or 'lung', and nobody will think anything of it.

it is not a rude word, but it is a private word它不是一個粗俗的字，但是一個私密的字——in normal daily talk people do not say it unless there is a reason平常說話的時候，人們不會沒事就說出這個字，like talking to a doctor, reading about health, or teaching a child the names of body parts除非有理由，像是跟醫生說話、讀健康資訊、或是教小孩身體部位的名稱。say it calmly, the same way you would say 'stomach' or 'lung'平靜地講出來就好，就像你講「stomach（胃）」或「lung（肺）」一樣，and nobody will think anything of it沒有人會覺得怎麼樣。

One thing worth knowing: many English speakers use 'vagina' loosely to mean the whole outside area too. In careful medical English, the outside parts have their own name — 'vulva' — and 'vagina' means only the inside tube. So when you read a health article and it seems to say two different things, that is why: the everyday use is wider than the medical use.

one thing worth knowing有一件事值得知道：many English speakers use 'vagina' loosely to mean the whole outside area too很多英文使用者會比較鬆散地用「vagina」來指整個外面的區域。in careful medical English在精確的醫學英文裡，the outside parts have their own name — 'vulva' —外面的部分有自己的名字——「vulva（外陰）」——and 'vagina' means only the inside tube而「vagina」只指裡面那條管道。so when you read a health article and it seems to say two different things所以當你讀健康文章，覺得它好像在講兩件不一樣的事，that is why原因就在這裡：the everyday use is wider than the medical use日常用法比醫學用法涵蓋得更廣。

The adjective is 'vaginal'.

the adjective形容詞形式 is 'vaginal'是「vaginal」。