Ge-grindan

According to the Old English Dictionary:

ge-grindan

p. -grand, pl. -grundon; pp. -grunden To grind together, sharpen, grind to powder; commolere, pertricare :-- Gegrindæs comminuet, Lk. Skt. Lind. 20, 18. Gegrunden [MS. gegrunde] commolitus, Ælfc. Gl. 36; Wrt. Voc. 28, 78. Gegrundene gáras the sharpened arrows, Byrht. Th. 134, 64; By. l09. DER. grindan. ge-grindan