Where does “brî” come from?
brî (Middle Low German) comes from Old Saxon brī, from Proto-West Germanic brīw, from Proto-Germanic brīwaz, from Proto-Germanic bʰréy-u-s ~ bʰr̥y-éw-s, from Proto-Indo-European bʰr-ey-, from Proto-Indo-European bʰer- — to bear, carry.
Ancestry of “brî”, step by step