Etymon
pie-sekw-protoindoeuropean-h2-protoindoeuropean-eh2-protoindoeuropean-sokweh2-protoindoeuropean-oy-protoindoeuropean-sokwh2oy-protoindoeuropean-yos-protoindoeuropean-sokwyos-protoitalic-sokjos-latin-sokios-latin-socius-protoindoeuropean-h2elder
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.