The Collaborative International Dictionary of English v.0.48:

Flicker \Flick"er\, n.
   1. The act of wavering or of fluttering; fluctuation; sudden
      and brief increase of brightness; as, the last flicker of
      the dying flame.
      [1913 Webster]

   2. (Zool.) The golden-winged woodpecker (Colaptes aurutus);
      -- so called from its spring note. Called also
      yellow-hammer, high-holder, pigeon woodpecker, and
      yucca.
      [1913 Webster]

            The cackle of the flicker among the oaks.
                                                  --Thoureau.
      [1913 Webster]