sirenomelia

From Ancient Greek Σειρήν (Seirḗn, “Siren from Greek mythology”) +‎ μέλος (mélos, “limb”) +‎ -εια (-eia, nominal suffix).

• (General American) IPA^(key): /ˌsaɪ.ɹən.oʊˈmi.liə/
• Rhymes: -iːliə

sirenomelia (uncountable)

1. (teratology) A rare congenital deformity in which the legs are fused together, giving them the appearance of a mermaid's tail.

• mermaidism
• mermaid syndrome

• sirenomelic

• “sirenomelia”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.