The Collaborative International Dictionary of English v.0.48:

Amaryllidaceae \Amaryllidaceae\ n.
   1. 1 a family of flowering plants including the snowdrop,
      narcissus, and daffodil; in some classification systems
      considered a subfamily of the Liliaceae.

   Syn: family Amaryllidaceae, amaryllis family
        [WordNet 1.5] Amaryllidaceous