The Collaborative International Dictionary of English v.0.48:

Dioscoreaceae \Dioscoreaceae\ n.
   1. a natural family of tuberous plants including the yams.

   Syn: family Dioscoreaceae, yam family.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Dioscoreaceae
    n 1: yams [syn: Dioscoreaceae, family Dioscoreaceae, yam
         family]