rest room不是“休息室”，dressing room也不是“试衣间”
通常在机场或者去到一些景点区域，我们会看到“rest room”这种标志。这时，你千万不要以为它是“休息室”的意思，这个短语的意思是“厕所”。比如饭店、商场，可以洗手上厕所的那种。
a room with toilets that is in a public place, for example in a restaurant
(公共场所的)盥洗室，洗手间，公共厕所
@Philip Newton：
Some people in western society consider elimination of bodily waste to be taboo; one does not talk about defecating or urinating 'in polite society’.
西方社会有些人认为清除身体排泄物是一种忌讳；在文明社会，人们不谈论排便或小便。
This sometimes even extends to the names of the rooms for such purposes; directly alluding to its purpose, such as calling it 'piss-house’, is seen as crude.
为此，这种观念甚至延伸到房间的名字上；用直接表明它用途的方式命名，比如称它为尿尿的房间，被认为是粗鲁的。
Thus people started using euphemisms: words that sound better because they are more remote or less direct.
因此，人们开始使用委婉语：那些听起来更好的词，因为它们更遥远或不那么直接。
So we got 'toilet’, from a French word for getting ready.
所以我们有了toilet这个词，它来自法语中的“准备”。
But after a while, using that term became associated with the porcelain object and it was no longer remote enough, so a new word was felt to be needed, and the 'euphemism treadmill’ continued.
但通过一段时间的使用，人们就把这个词和光溜溜的白瓷物体联系在一起，这样看起来就起不到不那么直接的作用了，所以是时候需要一个新词，让委婉继续。
The next, I think was, 'bathroom’; many such rooms also contain a toilet, and so one could say that one is going to the bathroom and pretend that it is to wash one’s hands or 'powder one’s nose’ (another euphemism).
下一个使用的词，我想是bathroom；很多bathroom也有厕所，所以你可以说你要去bathroom，然后假装是去洗手或擦鼻子(另一种委婉说法)。
But then that, too, became too directly associated with urinating.
但后来，这也和小便有了太直接的联系。
So next came 'restroom’: even more indirect and so even more polite.
接下来是restroom，更不那么直截了当，也更礼貌。
No doubt, in a few years or decades, even that will be felt to be too crude and another word will have to be thought up.
毫无疑问，再过几年或几十年，也许即使这样也会被认为太过粗鲁，不得不想出另一个词。
Note that in the UK, people seem to be fine with 'toilet’, generally speaking; if you ask to 'use the bathroom’, you might find yourself in a room with a bathtub and a sink but no commode.
请注意，一般来说，在英国，人们似乎对toilet没什么意见；如果你要求使用浴室，你可能会发现自己在一个房间里，有浴缸和水槽，但没有马桶。
dressing room≠试衣间 ？
正如上述提到的“rest room”不是“休息室”一样的道理，“dressing room”也不是“试衣间”。你可以单独拆开理解，dressing有穿衣打扮的意思，那么这个短语是“化妆间”的意思。
试衣间的英文是
a room or area in a shop where you can put on clothes to check that they fit before you buy them
商店里的一个房间或区域，你可以在买衣服前在那里检查衣服是否合身
今天的内容都学会了么？