Brim-wylf

According to the Old English Dictionary:

e;

brim-wylf

f. [brim, wylf a she-wolf] A sea-wolf; marina lupa. An epithet applied to Grendel's mother :-- Hine seó brimwylf abroten hæfde the sea-wolf had destroyed him, Beo. Th. 3202; B. 1599. brim-wylf