Source : Webster's Revised Unabridged Dictionary (1913)

Toggle \Tog"gle\, n. [Cf. {Tug}.] [Written also {toggel}.]
   1. (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.

   2. (Mach.) Two rods or plates connected by a toggle joint.

Source : WordNet®

toggle
     n 1: 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
     2: a hinged switch that can assume either of two positions
        [syn: {toggle switch}, {on-off switch}, {on/off switch}]
     3: 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)

toggle
     v 1: provide with a toggle or toggles
     2: fasten with, or as if with, a toggle
     3: release by a toggle switch; "toggle a bomb from an airplane"

Source : Free On-Line Dictionary of Computing

toggle
     
        To change a {bit} from whatever state it is in to the other
        state; to change from 1 to 0 or from 0 to 1.  This comes from
        "toggle switches", such as standard light switches, though the
        word "toggle" actually refers to the mechanism that keeps the
        switch in the position to which it is flipped rather than to
        the fact that the switch has two positions.  There are four
        things you can do to a bit: set it (force it to be 1), clear
        (or zero) it, leave it alone, or toggle it.
     
        [{Jargon File}]
     
        (1994-12-12)