Plain English Meaning

How hard something is pushing on a given amount of surface. If you press your thumb on a table, the harder you push, the more pressure you create on the spot under your thumb.

Full Definition

The amount of force applied per unit of area. In aviation maintenance it is commonly expressed in pounds per square inch (psi), inches of mercury (in. Hg), or pascals, and is measured in fluids (liquids and gases) acting against the walls of their container or against a surface.

Context Anchor

Seen in aircraft tires, oil systems, fuel systems, brake systems, weather reports, cabin systems, and instrument indications.