Ge-stíðian

According to the Old English Dictionary:

ge-stíðian

p. ode, ude; pp. od, ud To become hard, strong; indurare :-- Gistíðia induratam, Rtl. 102, 41. Mægen on him weóx and gestiðode his power waxed and was strengthened, Guthl. 2; Gdwn.12, 26. Ðá ðá he gestíðod wæs when he was grown up, Homl. Th. ii. 38, 3. ge-stiðian,ge-stiþian