排水

1. Origins, structure, and basic meaning

• Structure: 排水(はいすい) means draining water or the water discharged.
• Basic usage: It describes rainwater drainage or the treatment of water discharged from a factory.

2. Common pitfalls and similar expressions

• The action and the water itself
  • 排水する means to drain water, while 工場の排水 can refer to the water a factory discharges.
• Reading the word for a drain
  • 排水口 is read はいすいこう and means an opening or passage through which water drains.