The forces that prevent you from keeping someone else in slavery is coercion. So is the rule that says you're not allowed to walk out into the street and just have your way with someone without their consent. With such loose language, any type of society settlement in which people are born into a system that has rules that apply to them involves a type of coercion.

Since all people need to be cared for until a certain age, all people who survive past the first few days of their lives are born into coercion under a strict meaning of the word. Some would escape by living as hermits in desert land or remote islands that nobody cared to enforce law on. Hell - if you're going to be a pedant why restrict it to human coercion? The weather itself is a form of coercian. As are the laws of physics themselves.

Although in a strict sense you're right, I think you're wasting time. However, I have a morbid curiosity for some things and would be genuinely interested to learn what axe you're grinding.