boulder

irremovable boulders; irremovable obstacles.

the boulders look round and smooth.

boulders barred her passage.

a scatter of boulders round the pothole mouth.

They drilled boulder's for inserting dynamite.

a swift stream abrading boulders;

a boulder mantled with moss;

A flowing stream inarms a boulder in its passing.

Seals basked on boulders in a flat calm.

The river takes a headlong plunge into a maelstrom of rocks and boulders.

upper boulders were simply seated in the interstices below.

He took my hand to help me over a boulder that blocked the way.

Erratics ate boulders transported by glaciers and deposited some distance from their point of origin.