Definition
Shaped so that air flows smoothly around an object with minimal turbulence and drag. A streamlined body aligns with the relative wind so that airflow follows its contours rather than separating into disturbed, turbulent flow.
Plain English
Shaped so the air slides past it cleanly instead of getting churned up and slowing it down.
Context Anchor
Seen when describing aircraft shape, control-surface position, and any part that is designed to reduce air resistance in flight.
Derivation
From 'stream' (a smooth flow of fluid) and 'lined' (shaped along that line). The word literally describes a shape that follows the line of the flowing stream of air.
Why Pilots Care
Streamlined parts reduce drag, which improves speed, fuel efficiency, and the responsiveness of flight controls.
Intuition Check
Do not read “streamlined” as just “sleek-looking.” In aviation, it means shaped or positioned so air flows smoothly around it with reduced resistance.
Example Sentence 1
Retracting the landing gear after takeoff leaves the airplane in a more streamlined configuration, reducing drag.
Example Sentence 2
Fairings on the landing gear keep the struts streamlined so they disturb the airflow as little as possible.