The Collaborative International Dictionary of English v.0.48:

Flicker \Flick"er\ (fl[i^]k"[~e]r), v. i. [imp. & p. p.
   Flickered (fl[i^]k"[~e]rd); p. pr. & vb. n. Flickering.]
   [OE. flikeren, flekeren, to flutter, AS. flicerian,
   flicorian, cf. D. flikkeren to sparkle. [root]84. Cf.
   Flacker.]
   1. To flutter; to flap the wings without flying.
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            And flickering on her nest made short essays to
            sing.                                 --Dryden.
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   2. To waver unsteadily, like a flame in a current of air, or
      when about to expire; as, the flickering light.
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            The shadows flicker to fro.           --Tennyson.
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