The word slave arrived in English via the Old French sclave. In Medieval Latin the word was sclavus and in Byzantine Greek σκλάβος. Use of the word arose during the Early Medieval Period, when Slavs from Central and Eastern Europe (Saqaliba) were frequently enslaved by Moors from the Iberian Peninsula and North Africa.
There is a dispute among historians about whether terms such as "unfree labourer" or "enslaved …

Slavery by descent, also called chattel slavery, is the form most often associated with the word "slavery". In chattel slavery, the enslaved person is considered the personal property (chattel) of someone else, and can usually be bought and sold. It stems historically either from conquest, where a conquered person is enslaved, as in the Roman Empire or Ottoman Empire, or from slave raiding, as in the Atlantic slave trade. The number of people currently enslaved around the world …