Verified coincidence
A word that "rings across the world's tongues" only matters if the tongues are genuinely unrelated — otherwise you're just looking at cognates in disguise. So this Echo is falsifiable: every member is tagged with its Glottolog family, a form is promoted by how many unrelated families share it, and then the page attacks its own claim — it reads each member's Wiktionary etymology and demotes any pair that secretly shares a root. What survives is a verified accident of sound.
Babel
The same spelling, arrived at independently.