Brambliest refers to being full of prickly and thorny bushes, such as a tangled and overgrown patch of blackberries. The antonyms for this word would describe something smooth and obstacle-free. Words such as clear, smooth, unobstructed, open, and easy come to mind. These words convey an environment that is the complete opposite of a brambliest area. In other words, they describe a space that is free from any hindrance or difficulty, with no thorns, brush or obstacles that would impede movement. While brambliest suggests a place that is dense and chaotic, its antonyms evoke tranquility and order.