The term "Capitalism" was invented by Karl Marx, I refuse to use the language of Communists. I prefer "Free Enterprise".
The term and proper use of 'Capitalism' existed long before Marx. From an economic perspective, it actually is French in origin, with the first use of the term from Hollandische Mercurius in 1633 and referred to the new class of free laborers who exchanged goods with each other versus working on authority of the crown. This was even based on an earlier term, Capitale, which originated in the 12th century to refer to people who moved money or goods.
At that, Capitalism and Capitalist were common economic terms in use a century before Marx. In The Communist Manifesto, Marx only mentioned it in the context of Kapitalist and only referred to private ownership, it didn't even refer to the entire Capitalist system.
Marx tried to take an existing term and twist it into a negative. By saying it was 'his term' and refusing to use it, you are giving Marx what he wanted, making 'Capitalism' a negative.