toggle

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A pin, rod, or crosspiece fitted or inserted into a loop in a rope, chain, or strap to prevent slipping, to tighten, or to hold an attached object.
• noun A device or an apparatus with a toggle joint.
• intransitive verb To furnish or fasten with a toggle.
• intransitive verb To alternate between two or more electronic, mechanical, or computer-related options, usually by the operation of a single switch or keystroke.

from The Century Dictionary.

• noun A bar spanning (within) an opening in a tank or other structure, to which a lifting chain or sling can be secured in order to lift the structure. Also toggle-pin.
• To fasten (skins) together with wooden pins. Modern Amer.
• To lift or attach to a hoisting chain by means of a cross-bar inserted in a hole or angle.
• To fix or fasten (itself in something) like a toggle-iron; used reflexively, to stick fast.
• noun Nautical, a pin placed through the bight or eye of a rope, block-strap, or bolt, to keep it in its place, or to put the bight or eye of another rope upon, and thus secure them both together; also, a pin passed through a link of a chain which is itself passed through a link of the same or a different chain.
• noun Two rods or plates hinged together by a toggle-joint: a mechanical device for transmitting force or pressure at a right angle with its direction. See toggle-joint. and cut under stone-breaker.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Naut.) 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.
• noun (Mach.) Two rods or plates connected by a toggle joint.
• noun A toggle switch.
• transitive verb (Computer programming) To change the value of (a program variable) by activating a toggle switch.
• transitive verb a harpoon with a pivoted crosspiece in a mortise near the point to prevent it from being drawn out when a whale, shark, or other animal, is harpooned.
• transitive verb an elbow or knee joint, consisting of two bars so connected that they may be brought quite or nearly into a straight line, and made to produce great endwise pressure, when any force is applied to bring them into this position.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun 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, ring, or bight.
• noun A kind of button or frog capable of being readily engaged and disengaged for temporary purposes.
• noun 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)
• noun A toggle switch; a switch, usually with two positions, activated by a lever; an on/off switch.
• noun Scouting A circle of leather, plastic (Cub Scouts) etc, resembling a napkin holder to keep the neckerchief in place.
• verb to alternate between two positions using a single switch or lever.
• verb to switch between alternate states.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun 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)
• noun 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
• verb fasten with, or as if with, a toggle
• noun a hinged switch that can assume either of two positions
• verb release by a toggle switch
• verb provide with a toggle or toggles