Definition
The positions of an aircraft's trim devices (such as the elevator, rudder, or aileron trim tabs) selected by the pilot to relieve continuous control pressures and hold the airplane in a desired flight condition without sustained input on the controls.
Plain English
How the pilot has adjusted the trim so the airplane flies steadily on its own without them having to keep pushing or pulling on the controls.
Context Anchor
You encounter trim settings during climbs, descents, approaches, and energy corrections whenever speed, power, or flaps change.
Derivation
"Trim" comes from Old English trymman, meaning to arrange or set in proper order — originally used in sailing for adjusting sails and balancing a ship. In aviation it carries the same idea: setting the airplane in balance so it stays where the pilot wants it.
Why Pilots Care
Correct trim settings reduce workload and prevent unintended speed or altitude changes that can turn small energy errors into larger ones.
Intuition Check
Trim settings do not fly the airplane for you. They reduce the pressure you have to hold after you set the airplane where you want it.
Example Sentence 1
After leveling off at cruise altitude, the pilot adjusted the trim settings until the airplane held altitude with the controls released.
Example Sentence 2
During recovery from a low-energy state, the instructor reminded the student to reset the trim settings before attempting any further pitch changes.