Dingus

The dingus is the spring-loaded blade in the center of a Glock (and similar) trigger — a passive safety that prevents the trigger from moving rearward unless the shooter’s finger depresses the blade as part of a normal trigger press. Side-pressure (such as a holster or jacket drawstring snagging on the trigger from the side) won’t activate it. Universally referred to as dingus in shooter slang.