The Collaborative International Dictionary of English v.0.48:

Agnate \Ag"nate\, a. [L. agnatus, p. p. of agnasci to be born in
   addition to; ad + nasci (for gnasci) to be born. Cf.
   Adnate.]
   1. Related or akin by the father's side; also, sprung from
      the same male ancestor; as, agnate brother: a brother
      having the same father, but a different mother; in ths
      sense it is a correlative of uterine.
      [1913 Webster]

   2. Allied; akin. "Agnate words." --Pownall.
      [1913 Webster]

            Assume more or less of a fictitious character, but
            congenial and agnate with the former. --Landor.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Agnate \Ag"nate\, n. [Cf. F. agnat.] (Civil Law)
   A relative whose relationship can be traced exclusively
   through males.
   [1913 Webster]

WordNet (r) 3.0 (2006):

agnate
    adj 1: related on the father's side; "a paternal aunt" [syn:
           agnate, agnatic, paternal]
    n 1: one related on the father's side [syn: agnate,
         patrikin, patrilineal kin, patrisib, patrilineal
         sib]