In the Guardian’s list of “authorisms”:
The top 10 words invented by writers
i) One who sells services to employers without a long-term commitment to any of them.
ii) An uncommitted independent, as in politics or social life.
The word is not recorded before Sir Walter Scott introduced it in Ivanhoe which, among other things, is often considered the first historical novel in the modern sense. Scott’s freelancers were mercenaries who pledged their loyalty and arms for a fee. This was its first appearance: “I offered Richard the service of my Free Lances, and he refused them – I will lead them to Hull, seize on shipping, and embark for Flanders; thanks to the bustling times, a man of action will always find employment.”
The complete list is at http://www.theguardian.com/books/2014/nov/19/top-10-words-invented-writers-authorisms?CMP=twt_gu
Mind you, it makes me wonder how all the other words were invented. Probably in much the same way, just a little earlier in history.