Etymon
en-academic-protoindoeuropean-dheh1-protoindoeuropean-s-protoindoeuropean-dheh1s-protoitalic-faznom-latin-fanum-protoindoeuropean-h2-protoindoeuropean-eh2-protoindoeuropean-tos-protoindoeuropean-eh2tos-protoitalic-atos-latin-atus-protoindoeuropean-ikos-protoitalic-ikos-latin-icus-latin-aticus-latin-fanaticuslbor
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.