Source : Webster's Revised Unabridged Dictionary (1913)

Papa \Pa*pa"\, n. [F. papa, L. papa; cf. Gr. ?, ?, a child's
   word meaning father. Cf. {Pope}.]
   1. A child's word for father.

   2. A parish priest in the Greek Church. --Shipley.

Source : WordNet®

papa
     n : an informal term for a father; probably derived from baby
         talk [syn: {dad}, {dada}, {daddy}, {pa}, {pappa}, {pater},
          {pop}]