Definitions for "Thumbpiece"
(n.) A generally flat, projecting latch actuator found above a grip handle and depressed by the thumb. Source: Lock Industry Standards and Training (LIST) Council
Component located on the outside of a handleset which, when depressed, retracts the latchbolt.
Used on latchgrip handles, the thumbpiece is a metal lever that extends through the door to raise the bar in a rim latch assembly. Operated with the thumb.
Keywords:  flange, lid, hinged, pressed, raises
A flange attached to a hinged lid, which when pressed by the thumb raises the lid.