The Collaborative International Dictionary of English v.0.48:

Lycopsida \Lycopsida\ n.
   The class including club mosses and related forms: includes
   Lycopodiales; Isoetales; Selaginellales; and extinct
   Lepidodendrales; sometimes considered a subdivision of
   Tracheophyta.

   Syn: class Lycopsida, Lycopodiate, class Lycopodiate.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Lycopsida
    n 1: club mosses and related forms: includes Lycopodiales;
         Isoetales; Selaginellales; and extinct Lepidodendrales;
         sometimes considered a subdivision of Tracheophyta [syn:
         Lycopsida, class Lycopsida, Lycopodiate, class
         Lycopodiate]