The Collaborative International Dictionary of English v.0.48:

Slavery \Slav"er*y\, n.; pl. Slaveries. [See 2d Slave.]
   1. The condition of a slave; the state of entire subjection
      of one person to the will of another.
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            Disguise thyself as thou wilt, still, slavery, said
            I, still thou art a bitter draught!   --Sterne.
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            I wish, from my soul, that the legislature of this
            state [Virginia] could see the policy of a gradual
            abolition of slavery. It might prevent much future
            mischief.                             --Washington.
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   2. A condition of subjection or submission characterized by
      lack of freedom of action or of will.
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            The vulgar slaveries rich men submit to. --C. Lever.
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            There is a slavery that no legislation can abolish,
            -- the slavery of caste.              --G. W. Cable.
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   3. The holding of slaves.
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   Syn: Bondage; servitude; inthrallment; enslavement;
        captivity; bond service; vassalage.
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WordNet (r) 3.0 (2006):

slavery
    n 1: the state of being under the control of another person
         [syn: bondage, slavery, thrall, thralldom,
         thraldom]
    2: the practice of owning slaves [syn: slavery,
       slaveholding]
    3: work done under harsh conditions for little or no pay