Source : Webster's Revised Unabridged Dictionary (1913)

Patronymic \Pa`tro*nym"ic\, a. [L. patronymicus, Gr. ?; ? father
   + ? name: cf. F. patronymique.]
   Derived from ancestors; as, a patronymic denomination.

Patronymic \Pa`tro*nym"ic\, n. [Gr. ?.]
   A modification of the father's name borne by the son; a name
   derived from that of a parent or ancestor; as, Pelides, the
   son of Peleus; Johnson, the son of John; Macdonald, the son
   of Donald; Paulowitz, the son of Paul; also, the surname of a
   family; the family name. --M. A. Lower.

Source : WordNet®

patronymic
     adj : of a patronymic name
     n : a name derived with an affix (such as -son in English or O'-
         in Irish) from the name of your father or a paternal
         ancestor