Collateral Kinsmen
The Cyclopedic Law Dictionary · Walter A. Shumaker and George Foster Longsdorf; ed. James C. Cahill · 1922
The Cyclopedic Law Dictionary
Those who descend from one and the same common ancestor, but not from one another. Thus, brothers and sisters are collateral to each other; the uncle and nephew are collateral kinsmen, and cousins are the same. All kinsmen are either "lineal" or "collateral."