湖水

1. Origins, structure, and basic meaning

• Structure: 湖水 is read こすい and means lake water.
• Basic usage: It is used to describe a calm water surface or water collected for a quality test.

2. Common pitfalls and similar expressions

• Focus compared with 湖
  • 湖(みずうみ) refers to the lake as a geographical feature. 湖水を採取し focuses on collecting the water within it.