Godan verb with 'mu' ending, Intransitive verb
to become clear (water, air, etc.); to become transparent
水が底まで澄んでいる。The water is clear to the bottom. to resonate clearly (e.g. voice)
to become serene; to become tranquil; to be free of worries
to pronounce as an unvoiced sound
see 清音
Also written 清む【すむ】