Bi-worpen

Selon le Dictionnaire Anglo-Saxon :

bi-worpen

cast about, surrounded; cinctus :-- Is ðæt églond fenne biworpen the island is surrounded with a fen, Exon. 100 b; Th. 380, 9; Rä. 1, 5, = be-worpen; pp. of be-weorpan. bi-worpen