toggle
verb
°to alternate between two positions using a single switch or lever.
"Clicking a button will alternately toggle its light on OR off."
°to switch between alternate states.
"toggle to lower/upper case"
noun
°a switch that can assume either of two positions; an on/off switch.
°(nautical) A wooden or metal pin, short rod, crosspiece or similar used for securing a loop in a rope or chain, etc. (often temporarily) to another, e.g. a sea painter to a lifeboat. (FM 55-501).
synonyms: woggle