A clicker
is any device that makes a clicking sound, usually when deliberately activated
by its user.
For example, the clickers used in
clicker training are small hand-held devices that make a loud and consistent
sound to assist in training animals. They usually consist of a piece of thin
metal held in a
casing so that the metal is slightly torqued; depressing one end of the metal
causes it to pop out of alignment and releasing it causes it to pop back into
alignment, each time making a sharp click.
With some clickers, the user depresses the metal directly with thumb or
finger; with others, a button extends above the surface of the casing so that
depressing the button makes the metal click.
A clicker is also what some people call a
remote control.