Etymon
pie-tres-protoindoeuropean-yeti-protoindoeuropean-eyeti-protoindoeuropean-troseyeti-protoitalic-trozeo-latin-terreo-protoindoeuropean-os-protoindoeuropean-s-protoindoeuropean-os-protoitalic-os-latin-or-latin-terrorbor
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.