P / pressĭo
noun

pressĭo

gen. pressōnis · gender feminine · decl. 3rd
a pressing; pressing down; pressure
Lit., a pressing, pressing down, pressure (only in Vitruvius): pressio cacuminis, Vitr. 10, 8. —
the prop by extension
Transf., the prop or fulcrum under a lever while the burden is raised, Caes. B. C. 2, 9, 6: pressio, quod Graeci ὑπομόχλιον appellant, Vitr. 10, 8.