WordNet (r) 3.0 (2006):

Gnetopsida
    n 1: gymnospermous flowering plants; supposed link between
         conifers and angiosperms; in some systems classified as a
         class (Gnetopsida) and in others as a subdivision
         (Gnetophytina or Gnetophyta) [syn: Gnetopsida, class
         Gnetopsida, Gnetophytina, subdivision Gnetophytina,
         Gnetophyta]