Flint-grǽg

According to the Old English Dictionary:

flint-grǽg

adj. Flint-grey; cánus UNCERTAIN :-- Ic sceal to staðe þýwan [MS. þyran] flintgrǽgne flód I shall impel the flint-grey flood to the shore, Exon. 101b; Th. 383, 31; Rä. 4, 19. flint-græg