Source : Webster's Revised Unabridged Dictionary (1913)

Progenitor \Pro*gen"i*tor\, n. [OF. progeniteur, L. progenitor,
   fr. progignere, progenitum, to bring forth, to beget; pro
   forth + gignere to beget. See {Gender} kind.]
   An ancestor in the direct line; a forefather.

         And reverence thee their great progenitor. --Milton.

Source : WordNet®

progenitor
     n : an ancestor in the direct line [syn: {primogenitor}]