Nod n.
  1. A dropping or bending forward of the upper part or top of anything.
  Like a drunken sailor on a mast,
  Ready with every nod to tumble down.   --Shak.
  2. A quick or slight downward or forward motion of the head, in assent, in familiar salutation, in drowsiness, or in giving a signal, or a command; as, a nod of approval.
     A look or a nod only ought to correct them [the children] when they do amiss.   --Locke.
     Nations obey my word and wait my nod.   --Prior.
  The land of Nod, sleep.
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