Plain English Meaning
A small flap on the back edge of a stabilator that moves the same way the stabilator moves. It deliberately makes the controls feel heavier so the pilot does not move the stabilator too far too easily.
Full Definition
A small auxiliary control surface attached to the trailing edge of a stabilator that moves in the same direction as the stabilator. Its purpose is to increase the control force the pilot feels and to prevent the stabilator from being over-controlled. It also functions as a trim tab when adjusted by the pilot.
Context Anchor
Seen during tail inspection, control-surface rigging, and discussions of stabilator-equipped .