Noun
Something that toggles between two states or causes something else to toggle between two states.
A machine operator who is responsible for turning the machine on and off.
A type of fastener that has hinged wings that spread to provide a surface against which the fastener can be tightened (e.g. a toggle bolt).
A person occupied chaining up logs to prevent them from rolling off during transport on railroad cars and trucks.
A member of a bomber crew responsible dropping bombs from a wing plane at a signal from the lead bombardier.
Source: en.wiktionary.org