The Collaborative International Dictionary of English v.0.48:

Juncaceae \Juncaceae\ n.
   A natural family of tufted herbs resembling grasses,
   including the true rushes; called also the rush family.

   Syn: family Juncaceae, rush family.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Juncaceae
    n 1: tufted herbs resembling grasses: rushes [syn: Juncaceae,
         family Juncaceae, rush family]