Source : WordNet®

Arecidae
     n : one of four subclasses or superorder of Monocotyledones;
         comprises about 6400 species in 5 families of trees and
         shrubs and terrestrial herbs and a few free-floating
         aquatics including: Palmae; Araceae; Pandanaceae: and
         Lemnaceae [syn: {subclass Arecidae}]