The Collaborative International Dictionary of English v.0.48:

Homobasidiomycetes \Homobasidiomycetes\ n.
   A category used in some classification systems for various
   basidiomycetous fungi including e.g. mushrooms and puffballs
   which are usually placed in the classes Gasteromycetes and
   Hymenomycetes.

   Syn: subclass Homobasidiomycetes.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Homobasidiomycetes
    n 1: category used in some classification systems for various
         basidiomycetous fungi including e.g. mushrooms and
         puffballs which are usually placed in the classes
         Gasteromycetes and Hymenomycetes [syn:
         Homobasidiomycetes, subclass Homobasidiomycetes]