Grénian

According to the Old English Dictionary:

grénian

to become green, to flourish; virescere, Bt. Met. Fox 11, 114; Met. 11, 57. [A. R. greneþ; pres. indic: Ayenb. greni: Prompt. Parv. grenyn vireo; Icel. gróna: O. H. Ger. gruonan virescere: Ger. grünen.] grenian