A sex slave, a person who is forced against their will to perform, for another person or group, sexual acts on a regular or continuing basis.
An abject person.
A submissive partner in a BDSM relationship who (consensually) submits to (sexually and/or personally) serving one or more masters or mistresses.
A device (such as a secondary flash or hard drive) that is subject to the control of another (a master).
A person who is held in servitude as the property of another person, and whose labor (and often also whose body and life) is subject to the owner's volition and control.
A drudge; one who labors or is obliged (e.g. by prior contract) to labor like a slave with limited rights, e.g. an indentured servant.
One who has no power of resistance (to something), one who surrenders to or is under the domination (of something).
To work as a slaver, to enslave people.
To work hard.
To place a device under the control of another.