Wordnet 3.0
NOUN (1)
1. 
 any of various usually evergreen bog plants of the genus Parnassia having broad smooth basal leaves and a single pale flower resembling a buttercup; 
[syn: parnassia, grass-of-Parnassus]
The Collaborative International Dictionary of English v.0.48:
grass-of-Parnassus \grass-of-Parnassus\ n.
   Any of various usually evergreen bog plants of the genus
   Parnassia having broad smooth basal leaves and a single
   pale buttercuplike flower.
   Syn: parnassia, grass of Parnassus.
        [WordNet 1.5]
WordNet (r) 3.0 (2006):
grass-of-Parnassus
    n 1: any of various usually evergreen bog plants of the genus
         Parnassia having broad smooth basal leaves and a single
         pale flower resembling a buttercup [syn: parnassia,
         grass-of-Parnassus]