The Collaborative International Dictionary of English v.0.48:

Sufferance \Suf"fer*ance\, n. [OE. suffrance, OF. sufrance,
   soufrance, F. souffrance, L. sufferentia, from sufferens,
   -entis, p. pr. of sufferre. See Suffer.]
   1. The state of suffering; the bearing of pain; endurance.
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            He must not only die the death,
            But thy unkindness shall his death draw out
            To lingering sufferance.              --Shak.
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   2. Pain endured; misery; suffering; distress.
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            The seeming sufferances that you had borne. --Shak.
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   3. Loss; damage; injury. [Obs.]
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            A grievous . . . sufferance on most part of their
            fleet.                                --Shak.
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   4. Submission under difficult or oppressive circumstances;
      patience; moderation. --Chaucer.
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            But hasty heat tempering with sufferance wise.
                                                  --Spenser.
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   5. Negative consent by not forbidding or hindering;
      toleration; permission; allowance; leave. --Shak.
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            In their beginning they are weak and wan,
            But soon, through sufferance, grow to fearful end.
                                                  --Spenser.
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            Somewhiles by sufferance, and somewhiles by special
            leave and favor, they erected to themselves
            oratories.                            --Hooker.
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   6. A permission granted by the customs authorities for the
      shipment of goods. [Eng.]
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   Estate of sufferance (Law), the holding by a tenant who
      came in by a lawful title, but remains, after his right
      has expired, without positive leave of the owner.
      --Blackstone.

   On sufferance, by mere toleration; as, to remain in a house
      on sufferance.
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   Syn: Endurance; pain; misery; inconvenience; patience;
        moderation; toleration; permission.
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WordNet (r) 3.0 (2006):

sufferance
    n 1: patient endurance especially of pain or distress
    2: a disposition to tolerate or accept people or situations;
       "all people should practice toleration and live together in
       peace" [syn: toleration, acceptance, sufferance]

Moby Thesaurus II by Grady Ward, 1.0:

33 Moby Thesaurus words for "sufferance":
   acceptance, allowance, authorization, connivance, consent,
   endurance, forbearance, forbearing, forbearingness, fortitude,
   indulgence, leave, lenience, leniency, long-sufferance,
   long-suffering, longanimity, overlooking, patience,
   patience of Job, patientness, permissiveness, permit, perseverance,
   sanction, self-control, stoicism, sweet reasonableness, tolerance,
   toleration, waiting game, waiting it out, winking