slave (n.) Look up slave at Dictionary.com
late 13c., "person who is the property of another," from Old French esclave (13c.), from Medieval Latin Sclavus "slave" (cf. Italian schiavo, French esclave, Spanish esclavo), originally "Slav" (see Slav), so called because of the many Slavs sold into slavery by conquering peoples.
This sense development arose in the consequence of the wars waged by Otto the Great and his successors against the Slavs, a great number of whom they took captive and sold into slavery. [Klein]
Old English Wealh "Briton" also began to be used in the sense of "serf, slave" c.850; and Sanskrit dasa-, which can mean "slave," is apparently connected to dasyu- "pre-Aryan inhabitant of India."

More common Old English words for slave were þeow (related to þeowian "to serve") and þræl (see thrall). The Slavic words for "slave" (Russian rab, Serbo-Croatian rob, Old Church Slavonic rabu) are from Old Slavic *orbu, from the PIE root *orbh- (also source of orphan) the ground sense of which seems to be "thing that changes allegiance" (in the case of the slave, from himself to his master). The Slavic word is also the source of robot.

Applied to devices from 1904, especially those which are controlled by others (cf. slave jib in sailing, similarly of locomotives, flash bulbs, amplifiers). slave-driver is attested from 1807.
slave (v.) Look up slave at Dictionary.com
c.1600, "to enslave," from slave (n.). The meaning "work like a slave" is first recorded 1719. Related: Slaved; slaving.
Slave Look up Slave at Dictionary.com
Indian tribe of northwestern Canada, 1789, from slave (n.), translating Cree (Algonquian) awahkan "captive, slave."