Derived from the term Municipal, more specifically a Municipal
Golf Course. The term Mune is derogatory in nature, and is meant to describe a
stereotypical municipal golf course and/or the golfers that sometimes frequent these low-fee golf courses (bad conditions, cut-off jeans, tank tops, no shirts, toothless, swearing, etc).
However, the term is
universal. In most cases, it is used beyond the golf course context, and is synonymous with "Loser" or "Fool".