This pattern was interrupted by several large, dark, irregular openings in the object's surface.

He peered around the irregular opening to the outer ledge.

Along the walls were irregular openings from which shone a livid, yellow light.

It is an irregular opening in the ground, as though once, centuries ago, an ancient people tried to get out the precious metal.

Sarah Harding saw a dark irregular opening cut into the base of the cliff.

He described irregular openings through which the Indians passed in and out.

He pointed at an irregular opening in the rocky hillside.

Try this and you get an irregular opening.

It has very small and irregular openings ("eyes") distributed in the mass.

Or maybe, incredible thought, a small, irregular opening to the outside.