洗手间 (xǐshǒujiān) literally means "hand-washing room" and is a polite way to say "restroom" or "bathroom." It is commonly used in public settings and is considered more refined than alternatives like 厕所. You can use it to ask for directions or describe someone's location.
请问洗手间在哪儿?
Qǐngwèn xǐshǒujiān zài nǎr?
Excuse me, where is the restroom?
这家餐厅的洗手间非常干净。
Zhè jiā cāntīng de xǐshǒujiān fēicháng gānjìng.
The restroom at this restaurant is very clean.
他去洗手间了,马上就回来。
Tā qù xǐshǒujiān le, mǎshàng jiù huílái.
He went to the restroom and will be right back.