Source : Webster's Revised Unabridged Dictionary (1913)

Noddy \Nod"dy\, n.; pl. {Noddies}. [Prob. fr. nod to incline the
   head, either as in assent, or from drowsiness.]
   1. A simpleton; a fool. --L'Estrange.

   2. (Zo["o]l.)
      (a) Any tern of the genus {Anous}, as {A. stolidus}.
      (b) The arctic fulmar ({Fulmarus glacialis}). Sometimes
          also applied to other sea birds.

   3. An old game at cards. --Halliwell.

   4. A small two-wheeled one-horse vehicle.

   5. An inverted pendulum consisting of a short vertical flat
      spring which supports a rod having a bob at the top; --
      used for detecting and measuring slight horizontal
      vibrations of a body to which it is attached.