Is “capitalism” a misnomer?

The name “capitalism” derives from Marx’s false analogy between medieval land ownership and the “ownership of the means of production.” However, unlike medieval land, capital goods can be rented out, e.g., by Frank Knight’s entrepreneur, and then the capital owner does not hold those management or product rights. What then is the characteristic institution in our civilization? It is the voluntary renting of workers. What then is the relationship between Classical Liberalism, the dominant philosophy behind Economics, and a lifetime labour contract? Frank Knight had plenty to say about the doctrine of inalienable rights which disallows such contracts.