The Collaborative International Dictionary of English v.0.48:

Palmaceae \Palmaceae\ n.
   A natural family of chiefly tropical trees and shrubs and
   vines usually having a tall columnar trunk bearing a crown of
   very large leaves; coextensive with the order Palmales.

   Syn: Palmae, family Palmae, family Palmaceae, Arecaceae,
        family Arecaceae, palm family.
        [WordNet 1.5]