air brake; speedbrake
A device on an aircraft or vehicle that uses air resistance to reduce speed. In aviation, often a panel that extends from the wing or fuselage.
The pilot deployed the air brake during landing.
aerobraking; aerobrake
A spaceflight maneuver that uses a planet's atmosphere to slow a spacecraft. Distinct from the mechanical air brake on aircraft.
The Mars probe used aerobraking to enter orbit.