Source : Webster's Revised Unabridged Dictionary (1913)

Twig \Twig\, v. t. [imp. & p. p. {Twigged}; p. pr. & vb. n.
   {Twigging}.] [Cf. {Tweak}.]
   To twitch; to pull; to tweak. [Obs. or Scot.]

Source : WordNet®

twig
     n : small branch or division of a branch; usually applied to
         branches of the current or preceding year [syn: {branchlet},
          {sprig}]
     v 1: branch out in a twiglike manner; "The lightning bolt twigged
          in several directions"
     2: understand, usually after some initial difficulty; "She
        didn't know what her classmates were plotting but finally
        caught on" [syn: {catch on}, {get wise}, {get onto}, {tumble},
         {latch on}, {cotton on}, {get it}]
     [also: {twigging}, {twigged}]

twigging
     See {twig}