Cog-nā'tion, n.

n. [Lat. cognatio.] 1. Relation by descent from the same original; kindred. Two of which [vices] I shall mention as being of near cognation to it [ingratitude] and constant coherence with it. South.

2. Participation of the same nature. “A like temper and cognation.” Digby.
3. (Law.) That tie of consanguinity which exists between persons descended from the same father and mother; — used in distinction from agnation.

New Am. Cyc.