No he didn't. We have this thing called "language" and within the boundaries of language exist words. Words have definitions so that we understand what the other person is talking about. The word Mercenary is not a made up word that you get to decide what it means.
Used as a noun, this would be the definition:
Noun:
A professional soldier hired to serve in a foreign army.
"The best mercenaries of the 15th century were the Swiss. Their mobile pike-armed infantry squares were the dominant weapon system of the period.
"A nation of armed peasants, afflicted with the chronic overpopulation of the barren uplands, numerous enough to form massive columns of pikemen, they acquired by incessant practice the extraordinary perfection of skill and discipline demanded by their system of warfare, and they did this at home in their valleys, at no cost to their employers" (Kiernan 1957, p. 70).
The development of the Swiss tactical infantry made it imperative for states to organize the same kind of forces if they wished to survive (Redlich 1964, vol. i, p. 3). Feudal states lacked the administrative structure for the large-scale military organization required by this development, so they turned to the
military entrepreneur. Cities contracted with a
mercenary captain to supply a certain quantity and type of soldier. Hiring
mercenary companies was more efficient than hiring individuals since they were easier to hire and more effective fighters because of their experience of fighting together.4"
The swiss are just one example of an established organization with land (in this case a canton) that practiced merc work on a large organized scale. Going as far back as ancient roman times you had entire gallic tribes engaged in the practice. In the fractured pre-Italy medieval lands merc companies owned and administered lands. There's plenty more examples.
