Source : Webster's Revised Unabridged Dictionary (1913)

Fungi Imperfecti \Fun"gi Im`per*fec"ti\, pl. [L. imperfecti
   imperfect.] (Bot.)
   A heterogenous group of fungi of which the complete life
   history is not known. Some undoubtedly represent the conidium
   stages of various Ascomycetes. The group is divided into the
   orders Sph[ae]ropsidales, Melanconiales, and Moniliales.

Source : WordNet®

Fungi imperfecti
     n : large and heterogeneous form division of fungi comprising
         forms for which no sexually reproductive stage is known
         [syn: {Deuteromycota}, {subdivision Deuteromycota}, {Deuteromycotina},
          {subdivision Deuteromycotina}]