Plain English Meaning

The smooth, shaped panels that wrap around the engine. They keep the engine covered, guide cooling air to where it is needed, and let the air flow past the engine cleanly instead of crashing into it.

Full Definition

The streamlined metal or composite covers enclosing an aircraft engine. Engine cowlings shape the airflow around the engine, direct cooling air through and around the cylinders, and reduce the form drag the engine would otherwise produce if left exposed.

Context Anchor

Seen during preflight inspection, maintenance access, and discussions of form drag caused by the shape of aircraft parts.

Derivation

Cowling comes from cowl, an old word for a hooded garment worn by monks. The engine cover was named for the same reason — it is a hood that fits the engine. Knowing this makes the term less technical: it is simply the engine's hood.