Etymon
gem-bi-protowest-germanic-bi-old-english-be-middle-english-bi-english-be-protoindoeuropean-preyh-protoindoeuropean-os-protoindoeuropean-prihos-protogermanic-frijona-protogermanic-frijondz-protowest-germanic-friund-old-english-freond-middle-english-frend-english-friend-english-befriended-english-unbefriended-from-un-befriended
A dedicated page for this root is on the way — it will gather every word descended from it, sibling forms across daughter languages, and a branching map of the family tree.