any instruction that works first one way and then the other; it turns something on the first time it is used and then turns it off the next time
source: WordNet 3.0
a hinged switch that can assume either of two positions
source: WordNet 3.0
a fastener consisting of a peg or pin or crosspiece that is inserted into an eye at the end of a rope or a chain or a cable in order to fasten it to something (as another rope or chain or cable)
source: WordNet 3.0
A wooden pin tapering toward both ends with a groove around its middle, fixed transversely in the eye of a rope to be secured to any other loop or bight or ring; a kind of button or frog capable of being readily engaged and disengaged for temporary purposes.