Merriam-Webster's Collegiate® Dictionary, 11th Edition
TOGGLE
I. noun
Etymology: origin unknown
Date: circa 1775
a piece or device for holding or securing: as, a pin inserted in a nautical knot to make it more secure or easier to slip, a crosspiece attached to the end of or to a loop in something (as a chain, rope, line, strap, or belt) usually to prevent slipping, to serve in twisting or tightening, or to hold something attached, a device consisting of two bars jointed together end to end but not in line so that when a force is applied to the joint tending to straighten it pressure will be exerted on the parts adjacent or fixed to the outer ends of the bars,
II. verb (toggled; toggling)
Date: 1836
transitive verb to fasten with or as if with a toggle, to furnish with a toggle, intransitive verb to switch between two options especially of an electronic device usually by pressing a single button or a simple key combination