澄ます

1. Origins, structure, and basic meaning

• Structure: 澄ます, read すます, is the transitive counterpart formed from the intransitive verb 澄む, “to become clear.”
• Basic usage: 水を澄ます means making water clear, while 澄ました顔 is a composed or innocent-looking expression.

2. Common pitfalls and similar expressions

• Distinguishing meanings
  • The object distinguishes removing physical cloudiness from figuratively presenting a composed demeanor.