Freethinking is the habit of forming your own opinions, ideas, and beliefs instead of swallowing what other people tell you. English also uses it as an adjective: a freethinking writer, a freethinking school. Like freethinker, it is used with approval, and it sounds a bit bookish. Though actually, people sometimes stretch it to mean anyone a little rebellious, even when that person is not really examining ideas — just refusing rules. The careful meaning is independent thought, not being wild. It names the way of thinking (or that kind of person in a loose, approving way); freethinker is the clearer word for the person.