Source : Webster's Revised Unabridged Dictionary (1913)

Annunciation lily \An*nun`ci*a"tion lil"y\ (Bot.)
   The common white lily ({Lilium candidum}). So called because
   it is usually introduced by painters in pictures of the
   Annunciation.

Easter lily \Eas"ter lil`y\ (Bot.)
   Any one of various lilies or lilylike flowers which bloom
   about Easter; specif.:
   (a) The common white lily ({Lilium candidum}), called also
       {Annunciation lily}.
   (b) The larger white lily ({Lilium longiflorum eximium}, syn.
       {L. Harrisii}) called also {Bermuda lily}.
   (c) The daffodil ({Narcissus Pseudo-Narcissus}).
   (d) The Atamasco lily.

Source : WordNet®

Annunciation lily
     n : lily of eastern Mediterranean and the Balkans with broad
         funnel-shaped white flowers [syn: {Madonna lily}, {white
         lily}, {Lent lily}, {Lilium candidum}]