grange (Old French) comes from Latin granicārium, from Vulgar Latin granica, from Latin grānum, from Proto-Italic grānom, from Proto-Indo-European ǵr̥h₂nóm, from Proto-Indo-European ǵr̥h₂nós, from Proto-Indo-European ǵerh₂- — to grow old, to mature.
grange (Old French): granary; barn; grange; small farm