Etymon
enm-counter-english-counter-latin-arguo-protoindoeuropean-mn-protoindoeuropean-mntom-protoitalic-mntom-latin-mentum-latin-argumentum-protoindoeuropean-h2-protoindoeuropean-eh2-protoindoeuropean-yeti-protoindoeuropean-eh2yeti-protoitalic-ao-latin-o-latin-argumentor-protoindoeuropean-wos-protoindoeuropean-ihwosder
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.