Refers to a patch of deep, soft mud, often on a road or path after rain. Can also mean the mud itself.
The road after the rain was full of muddy patches.
The car got stuck in the mud and couldn't move.
Usually written in kana; the kanji form 泥濘 is rare and literary.
Rare kanji form; the reading is a jukujikun (special kanji reading).
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.