Slave: Person who gives up a great degree of control in an ongoing D/s relationship, sometimes with few remaining limits. Often those who identify as "slave" have a great desire for being of service to their dominant, sometimes referred to as "service-oriented submission."

that is what wiki has to say on the matter.

I fully agree with Dragon's muse. It isn't that a "Slave has no self respect. They know and love there "Master/Dom/Lord/King" to the point that they have little to no fear of them going past their limits. About the time a Sub lets me put my brand on her I will call her slave. At that point she is mine for ever and always. I am also hers forever and always.