Definitions

1. adjective

overgrown with thick underbrush, especially brambles or thorns; dense and tangled with vegetation

“The hikers had to navigate through the pruinous undergrowth to reach the summit.”

2. noun

a plant or part of a plant that has become overgrown and dense with thorns, etc.

“The pruinous mass of thorns and brambles made it difficult to pass through the forest.”