Etymon
enm-meridian-english-meridian-protoitalic-wre-latin-re-protoindoeuropean-spend-protoindoeuropean-spondeyeti-protoitalic-spondejo-protoitalic-spondeo-latin-spondeo-latin-respondeo-latin-responsumbor
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.