noun
Refers to a patch of deep, soft mud, often on a road or path after rain. Can also mean the mud itself.
雨上がりの道はぬかるみだらけだった。
The road after the rain was full of muddy patches.
車がぬかるみにはまって動けなくなった。
The car got stuck in the mud and couldn't move.
Derived from the verb ぬかる (to be muddy) + nominalizing suffix み, indicating a place or state. The kanji 泥濘 is a jukujikun reading, where the characters are assigned based on meaning rather than sound.