The Collaborative International Dictionary of English v.0.48:

Fungi \Fun"gi\ (f[u^]n"j[imac]), n. pl.; sing. fungus. (Biol.)
   A group of thallophytic plant-like organisms of low
   organization, destitute of chlorophyll, in which reproduction
   is mainly accomplished by means of asexual spores, which are
   produced in a great variety of ways, though sexual
   reproduction is known to occur in certain Phycomycetes, or
   so-called algal fungi. They include the molds, mildews,
   rusts, smuts, mushrooms, toadstools, puff balls, and the
   allies of each. In the two-kingdom classification system they
   were classed with the plants, but in the modern five-kingdom
   classification, they are not classed as plants, but are
   classed in their own separate kingdom fungi, which includes
   the phyla Zygomycota (including simple fungi such as bread
   molds), Ascomycota (including the yeasts), Basidiomycota
   (including the mushrooms, smuts, and rusts), and
   Deuteromycota (the fungi imperfecti). Some of the forms,
   such as the yeasts, appear as single-celled microorganisms,
   but all of the fungi are are eukaryotic, thus distinguishing
   them from the prokaryotic microorganisms of the kingdon
   Monera.
   [Webster 1913 Suppl. +PJC]

   Note: The Fungi appear to have originated by degeneration
         from various alg[ae], losing their chlorophyll on
         assuming a parasitic or saprophytic life. In an earlier
         classification they were divided into the subclasses
         Phycomycetes, the lower or algal fungi; the
         Mesomycetes, or intermediate fungi; and the
         Mycomycetes, or the higher fungi; by others into the
         Phycomycetes; the Ascomycetes, or sac-spore fungi;
         and the Basidiomycetes, or basidial-spore fungi.
         [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

Fungus \Fun"gus\, n.; pl. L. Fungi, E. Funguses. [L., a
   mushroom; perh. akin to a doubtful Gr. ? sponge, for ?; if
   so, cf. E. sponge.]
   1. (Bot.) Any one of the Fungi, a large and very complex
      group of thallophytes of low organization, -- the molds,
      mildews, rusts, smuts, mushrooms, toadstools, puff balls,
      and the allies of each. See fungi.
      [1913 Webster]

   Note: The fungi are all destitute of chorophyll, and,
         therefore, to be supplied with elaborated nourishment,
         must live as saprophytes or parasites. They range in
         size from single microscopic cells to systems of
         entangled threads many feet in extent, which develop
         reproductive bodies as large as a man's head. The
         vegetative system consists of septate or rarely
         unseptate filaments called hyph[ae]; the aggregation of
         hyph[ae] into structures of more or less definite form
         is known as the mycelium. See Fungi, in the
         Supplement.
         [1913 Webster]

   2. (Med.) A spongy, morbid growth or granulation in animal
      bodies, as the proud flesh of wounds. --Hoblyn.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Cryptogamia \Cryp`to*ga"mi*a\ (kr?p`t?-g?"m?-?), n.; pl.
   Cryptogami[ae] (-?). [NL., fr. Gr. krypto`s hidden, secret
   + ga`mos marriage.] (Bot.)
   The series or division of flowerless plants, or those never
   having true stamens and pistils, but propagated by spores of
   various kinds.
   [1913 Webster]

   Note: The subdivisions have been variously arranged. The
         following arrangement recognizes four classes: -- I.
         Pteridophyta, or Vascular Acrogens.} These include
         Ferns, Equiseta or Scouring rushes, Lycopodiace[ae]
         or Club mosses, Selaginelle[ae], and several other
         smaller orders. Here belonged also the extinct coal
         plants called Lepidodendron, Sigillaria, and
         Calamites. II. Bryophita, or Cellular Acrogens.
         These include Musci, or Mosses, Hepatic[ae], or
         Scale mosses and Liverworts, and possibly
         Charace[ae], the Stoneworts. III. Alg[ae], which
         are divided into Floride[ae], the Red Seaweeds, and
         the orders Dictyote[ae], Oospore[ae],
         Zoospore[ae], Conjugat[ae], Diatomace[ae], and
         Cryptophyce[ae]. IV. Fungi. The molds, mildews,
         mushrooms, puffballs, etc., which are variously grouped
         into several subclasses and many orders. The Lichenes
         or Lichens are now considered to be of a mixed nature,
         each plant partly a Fungus and partly an Alga.
         [1913 Webster] Cryptogamic
         Cryptogamian

WordNet (r) 3.0 (2006):

Fungi
    n 1: the taxonomic kingdom including yeast, molds, smuts,
         mushrooms, and toadstools; distinct from the green plants
         [syn: Fungi, kingdom Fungi, fungus kingdom]