expression, ichidan verb
get covered in mud; be smeared with mud
Describes becoming thoroughly dirty with mud, often through an accident or messy situation.
雨の日に山道を歩いて、服が泥に塗れた。
Walking on a mountain trail on a rainy day, my clothes got covered in mud.
泥まみれ is a noun/adjectival noun meaning 'covered in mud' as a state, while 泥に塗れる is a verb phrase focusing on the action or process of becoming muddy.
The expression combines 泥 (mud) with the particle に and the verb 塗れる (to be smeared/covered). The verb 塗れる itself is of native Japanese origin, related to the idea of being daubed or stained.