n. A person who knows a lot about one thing, and very little about anything else.
2010
Vinnie, the quintessential polymath as defined in the book, starts by observing that for the most part today, most of us seem to specialize and highlights the fact that we are monomaths in a world of exploding knowledge and passionately argues for more and more polymaths to be nurtured both at the institutional and at personal levels. (Being a monomath is a direct teaching of many management thinkers of recent era – for example, as recently as in the last two decades, Jim Collins adopted Peter Drucker’s thinking and brought out in his book "Good to Great" that leaders need to think and act like hedgehogs , not foxes. Hedgehogs are more like monomaths and foxes are more like polymaths ).
2009
It is not only the explosion of knowledge that puts polymaths at a disadvantage, but also the vast increase in the number of specialists and experts in every field. This is because the learning that creates would-be polymaths creates monomaths too and in overwhelming numbers.
1990 (earliest)
Monomath: "a person with an exhaustive knowledge of a single, often utterly trivial, subject."