Plain English Meaning

Air that has been squeezed into a smaller space so it is denser and at higher pressure than the outside air.

Full Definition

Air that has been compressed to a pressure higher than the surrounding atmosphere, usually by a turbocharger or supercharger, before being delivered to the engine's induction system.

Context Anchor

Seen in reciprocating engine discussions when air is compressed before entering the engine so the engine can keep producing power, especially as the airplane climbs.

Derivation

From Latin pressus, meaning 'pressed.' Pressurized air is literally air that has been pressed together, packing more air molecules into the same volume.

Why Pilots Care

Maintains engine power output as increases and outside air thins.