Definition
The cockpit control used by the pilot to set engine power on a jet aircraft. Moving the thrust lever forward commands the engine to produce more thrust; pulling it back commands less. It is the jet equivalent of the throttle in a piston-engine airplane, but it directly controls engine thrust output rather than fuel/air mixture to a piston engine.
Plain English
The hand-operated lever in the cockpit that the pilot pushes forward to make a jet engine push harder, and pulls back to make it push less.
Context Anchor
Seen on the cockpit power controls in jet airplanes, especially during engine start, taxi, takeoff, climb, approach, and landing.
Derivation
From 'thrust' (the forward-pushing force the engine produces) and 'lever' (a hand-operated control). Called a 'thrust lever' rather than a 'throttle' because in a jet, the pilot is commanding a level of thrust output, not directly metering fuel as in a piston engine.
Why Pilots Care
Correct movement of the thrust levers is required for safe takeoff performance, efficient cruise, and controlled descents while protecting the engines from overstress.
Analogy
It works like the accelerator pedal in a car, except the engine responds by producing a chosen amount of push rather than a chosen RPM.
Intuition Check
Do not think of the thrust lever as a simple gas pedal that gives instant response. In a jet, moving the thrust lever commands the engine to change thrust, and the engine may take a short time to respond.
Example Sentence 1
On final approach, the pilot made small thrust lever adjustments to hold the target airspeed.
Example Sentence 2
During descent the pilot slowly retarded the thrust levers to maintain the target airspeed.