The Definition of Slavery in International Law

As a slavery abolitionists it's amazing that after all this time, blood, destruction, and suffering, we still don't know what the most basic terms which define the history of this country mean. Ask ten people to define slavery and see what you get.
Next try it with race/racism. Even the word abolition has been co-opted and redefined.
Normally when you ask someone to define these terms they'll tell you what they think as if guesses (educated or not) are perfectly acceptable because no one agrees on any particular definition. Sirius B?

How can everyone in this country who has ever went to school not know the answer to this immediately? It's only been over 4 hunnit gotdam years of it being the source of our woes right? Right?!

We're going to help with that problem. We've searched the records nationally and internationally to find a detailed definition which is legally accepted nearly worldwide. I've consulted with experts and taken council. Today, we'll answer the question; What is Slavery?
So you won't have to guess no more.