Source : Webster's Revised Unabridged Dictionary (1913)

Zigzag \Zig"zag`\, v. i.
   To move in a zigzag manner; also, to have a zigzag shape.
   --R. Browning.

Zigzag \Zig"zag`\, n. [F. zigzag, G. zickzack, from zacke,
   zacken, a dentil, tooth. Cf. {Tack} a small nail.]
   1. Something that has short turns or angles.

            The fanatics going straight forward and openly, the
            politicians by the surer mode of zigzag. --Burke.

   2. (Arch.) A molding running in a zigzag line; a chevron, or
      series of chevrons. See Illust. of {Chevron}, 3.

   3. (Fort.) See {Boyau}.

Zigzag \Zig"zag`\, a.
   Having short, sharp turns; running this way and that in an
   onward course.

Zigzag \Zig"zag`\, v. t. [imp. & p. p. {Zigzagged}; p. pr. & vb.
   n. {Zigzagging}.]
   To form with short turns.

Source : WordNet®

zigzag
     adj : having short sharp turns or angles
     [also: {zigzagging}, {zigzagged}]

zigzag
     n : an angular shape characterized by sharp turns in alternating
         directions [syn: {zig}, {zag}]
     adv : in a zigzag course or on a zigzag path; "birds flew zigzag
           across the blue sky"
     v : travel along a zigzag path; "The river zigzags through the
         countryside" [syn: {crank}]
     [also: {zigzagging}, {zigzagged}]