Verb (5-dan, む, intransitive)
1. to become clear (water, air, etc.); to become transparent
今日は空気が澄んでますね。The air is clear today, isn't it?
2. to resonate clearly (e.g. voice)
澄んだいい声だった。It was a clear, nice voice.
3. to become serene; to become tranquil; to be free of worries
あなたは世界の誰よりも澄んだ心を持っているのです。You have a purer heart than anyone else in the world.
4. to pronounce as an unvoiced sound