Ge-beterian

According to the Old English Dictionary:

-betrian;

ge-beterian

p. ode; pp. od [ge-, beterian to make better, betera better] To better, make better; meliōrāre, emendāre :-- Ðe mid ðære láre gebeterode wǽron who were bettered by that instruction, Homl. Th. i. 406, 32. Ða scamfæstan beóþ oft mid gemetlícre láre gebetrode the modest are often improved with moderate instruction. Past. 31, 1; Swt. 205, 23; Hat. MS. 39 b, 5. ge-beterian