The Collaborative International Dictionary of English v.0.48:

Lutein \Lu"te*in\, n. [From corpus luteum.] (Physiol. Chem.)
   A substance of a strongly marked yellow color, extracted from
   the yolk of eggs, and from the tissue of the corpus luteum.
   [1913 Webster]

WordNet (r) 3.0 (2006):

lutein
    n 1: yellow carotenoid pigments in plants and animal fats and
         egg yolks [syn: xanthophyll, xanthophyl, lutein]