[struggle]

The word “slave” comes from “Slav,” as the Ottoman Turks often used people of Slavic origin as slaves.

[Verginius Rufus]

Yes, "slave" comes from "Slav" because so many Slavs were enslaved, but the term dates back centuries before the Ottoman Turks began their conquests. Medieval Europeans would enslave pagans and since Eastern Europe was Christianized later, that was where a lot of the slaves came from.

It's also true that the Ottoman Turks enslaved many Christians, including many Slavs. Of course they also killed a lot of Christians too (but the dead ones were useless for labor).