>If you speak one language you’re normal. Two you are bi-lingual. 5 you are polyliguist. >You don’t have to speak every one of the 7000 languages there are said to be just to be one. One guy (Mesic) apparently reported to understand 73. And another guy (Fazah) claimed 53.

"Polymath" is not a neologism. It has an already established, very specific meaning. You do not need to derive its individual components. It's very decidedly not a synonym to "person who is very very good within this very narrow subject area" (that would be an "expert") - quite the contrary! That's why "polymath of economics" or similar is a contradiction.

> Knowledge is a vast, vast domain and some people become competent or masters of one domain in a matter of several years.

Sure? But the natural conclusion from that is that it is simply no longer possible for a human to become a polymath, since it is no longer possible to keep up with the entire sea of human knowledge. Being a polymath is, at best, a 19th-century thing. Changing the meaning of "polymath" in order to be able to use the word in a contemporary context again, which is what the source article seems to be doing, seems a bit silly to me.