Etymon
en-bio-protoindoeuropean-h2eg-protoindoeuropean-eti-protoindoeuropean-h2egeti-protoitalic-ago-latin-ago-protoindoeuropean-tus-protoitalic-tus-latin-tus-latin-actus-protoindoeuropean-h2-protoindoeuropean-eh2-protoindoeuropean-yeti-protoindoeuropean-eh2yeti-protoitalic-ao-latin-o-latin-actuo-medieval-latin-actuatusder
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.