Source : Webster's Revised Unabridged Dictionary (1913)

Homunculus \Ho*mun"cu*lus\, n.; pl. {Homunculi}. [L., dim. of
   homo man.]
   A little man; a dwarf; a manikin. --Sterne.

Source : WordNet®

homunculus
     n 1: a person who is very small but who is not otherwise deformed
          or abnormal [syn: {manikin}, {mannikin}]
     2: a tiny fully formed individual that (according to the
        discredited theory of preformation) is supposed to be
        present in the sperm cell
     [also: {homunculi} (pl)]

homunculi
     See {homunculus}