Clicker

noun

1. The remote-control device used to change settings on a television set, VCR, or other electronic equipment.

   "We have a clicker for the TV, one for the VCR, one for the DVD player and another one that does it all."

2. An electronic device used by individual students in the classroom to respond to multiple-choice questions, etc.
3. A person who cuts out the uppers of shoes from pieces of leather using a flexible knife that clicks as it changes direction.
4. A machine that cuts materials using a steel rule die. The name comes from the sound (click) when the material is cut. May be hand, pneumatic, or hydraulic powered.
5. A signalling device used by military forces. Pressed between thumb and fingers, it makes a small but distinctive click understood by other members of a unit.