Wordnet 3.0
NOUN (1)
1. 
 either of two yellow to red retinal pigments formed from rhodopsin by the action of light; 
[syn: retinene, retinal]
WordNet (r) 3.0 (2006):
retinene
    n 1: either of two yellow to red retinal pigments formed from
         rhodopsin by the action of light [syn: retinene,
         retinal]