The Collaborative International Dictionary of English v.0.48:

Gasteromycetes \Gas`te*ro*my*ce"tes\, n. pl. [NL., from Gr. ?
   stomach + ? a mushroom.] (Bot.)
   An order of fungi, in which the spores are borne inside a sac
   called the peridium, as in the puffballs.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Gasteromycetes
    n 1: fungi in which the hymenium is enclosed until after spores
         have matured: puffballs; earth stars; stinkhorn fungi [syn:
         Gasteromycetes, class Gasteromycetes, Gastromycetes,
         class Gastromycetes]