Why is it called a mantle?

Why is it called a mantle?" I queried, looking for clarification. The term seemed intriguing, yet opaque to my understanding. Was it named for its protective qualities, shielding its wearer from harm? Or did it derive from its draping elegance, resembling the cloak worn by ancient heroes? "I'm curious," I continued, "is it a reference to its historical significance, or perhaps a nod to its symbolic meaning? It seems to carry weight, not just physically but also metaphorically. Could you please elaborate on the etymology of this term? I'm eager to delve deeper into its origins and understand the reason behind its nomenclature." My tone was one of genuine interest and curiosity, seeking to unwrap the layers of meaning hidden within this seemingly simple word. I was hopeful that the explanation would reveal not only the literal meaning of the term but also its deeper cultural and historical significance.