Source : Webster's Revised Unabridged Dictionary (1913)

Fatherless \Fa"ther*less\, a.
   1. Destitute of a living father; as, a fatherless child.

   2. Without a known author. --Beau. & Fl.

Source : WordNet®

fatherless
     adj 1: having no living father
     2: not having a known or legally responsible father