Before revision: Although the exact etymology is obscure, the English and Frisian forms probably derive from an earlier Anglo-Frisian *bō-ja ("little brother"), a diminutive of the Germanic root *bō- ("brother, male relation"), from Proto-Indo-European *bhā-, *bhāt- ("father, brother , servant ").
After revision: Although the exact etymology is obscure, the English and Frisian forms probably derive from an earlier Anglo-Frisian *bō-ja ("little brother"), a diminutive of the Germanic root *bō- ("brother, male relation"), from Proto-Indo-European *bhā-, *bhāt- ("father, brother ").