Source : Webster's Revised Unabridged Dictionary (1913)

Puffball \Puff"ball`\, n. (Bot.)
   A kind of ball-shaped fungus ({Lycoperdon giganteum}, and
   other species of the same genus) full of dustlike spores when
   ripe; -- called also {bullfist}, {bullfice}, {puckfist},
   {puff}, and {puffin}.

Source : WordNet®

puffball
     n 1: any of various fungi of the family Lycoperdaceae whose round
          fruiting body discharges a cloud of spores when mature
          [syn: {true puffball}]
     2: any of various fungi of the genus Scleroderma having
        hard-skinned subterranean fruiting bodies resembling
        truffles [syn: {earthball}, {false truffle}, {hard-skinned
        puffball}]