Bone, parietal: The main bone on the side of the skull.
Although the parietal bone is curved, it is considered a flat bone (as opposed to a tubular bone). The parietal bone is shaped like an irregular quadrangle. It articulates (joins) with the other parietal bone in the midline (top of the head), with the frontal bone in front of it, with the occipital bone behind it, and with the sphenoid and temporal bones lower down on the side of the skull.
The word "parietal" comes from the Latin "parietalis" meaning "belonging to the wall."