godan verb (-mu), intransitive verb
stagnate; become still
Archaic intransitive verb describing water or a situation becoming stagnant or still. Not used in modern Japanese; replaced by よどむ or 停滞する.
古い和歌に「瀞む水」という表現が見られる。
The expression 'stagnant water' can be found in old waka poetry.
The exact derivation is uncertain; it is an archaic verb related to the concept of stillness or stagnation, possibly sharing roots with とどこおる (滞る).