Here’s an interesting word.

The is old English from the Latin and means “wall”.

So first it means the wall of a body cavity. Then the wall of a hollow structure.

And then it came to stand for the rules for opposite sex visiting in dormitories – rules that kept a “wall” of separation between the sexes.

And finally it became the name of the prehistoric art painted on the walls of caves 30-40,000 yrs ago which came to be called parietal art.

Handprints at Cueva De Las Manos. H_ctor Aviles / EyeEm / Getty Images

From: everythingdordogne.net

parietal | pəˈrīəd(ə)l | adjective 1 Anatomy & Biology of, relating to, attached to, or denoting the wall of the body or of a body cavity or hollow structure. • of the parietal lobe: the parietal cortex. 2 North American relating to residence in a college or university dormitory and especially to visits from members of the opposite sex: parietal rules. 3 Archaeology denoting prehistoric art found on rock walls. noun 1 Anatomy & Zoology a parietal structure. • short for parietal bone.2 (parietals) informal dormitory rules governing visits from members of the opposite sex. ORIGIN late Middle English: from late Latin parietalis, from Latin paries, pariet- ‘wall’.