The Collaborative International Dictionary of English v.0.48:

Fee \Fee\ (f[=e]), n. [OE. fe, feh, feoh, cattle, property,
   money, fief, AS. feoh cattle, property, money; the senses of
   "property, money," arising from cattle being used in early
   times as a medium of exchange or payment, property chiefly
   consisting of cattle; akin to OS. fehu cattle, property, D.
   vee cattle, OHG. fihu, fehu, G. vieh, Icel. f[=e] cattle,
   property, money, Goth. fa['i]hu, L. pecus cattle, pecunia
   property, money, Skr. pa[,c]u cattle, perh. orig., "a
   fastened or tethered animal," from a root signifying to bind,
   and perh. akin to E. fang, fair, a.; cf. OF. fie, flu, feu,
   fleu, fief, F. fief, from German, of the same origin. the
   sense fief is due to the French. [root]249. Cf. Feud,
   Fief, Fellow, Pecuniary.]
   1. property; possession; tenure. "Laden with rich fee."
      --Spenser.
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            Once did she hold the gorgeous East in fee.
                                                  --Wordsworth.
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   2. Reward or compensation for services rendered or to be
      rendered; especially, payment for professional services,
      of optional amount, or fixed by custom or laws; charge;
      pay; perquisite; as, the fees of lawyers and physicians;
      the fees of office; clerk's fees; sheriff's fees; marriage
      fees, etc.
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            To plead for love deserves more fee than hate.
                                                  --Shak.
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   3. (Feud. Law) A right to the use of a superior's land, as a
      stipend for services to be performed; also, the land so
      held; a fief.
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   4. (Eng. Law) An estate of inheritance supposed to be held
      either mediately or immediately from the sovereign, and
      absolutely vested in the owner.
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   Note: All the land in England, except the crown land, is of
         this kind. An absolute fee, or fee simple, is land
         which a man holds to himself and his heirs forever, who
         are called tenants in fee simple. In modern writers, by
         fee is usually meant fee simple. A limited fee may be a
         qualified or base fee, which ceases with the existence
         of certain conditions; or a conditional fee, or fee
         tail, which is limited to particular heirs.
         --Blackstone.
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   5. (Amer. Law) An estate of inheritance belonging to the
      owner, and transmissible to his heirs, absolutely and
      simply, without condition attached to the tenure.
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   Fee estate (Eng. Law), land or tenements held in fee in
      consideration or some acknowledgment or service rendered
      to the lord.

   Fee farm (Law), land held of another in fee, in
      consideration of an annual rent, without homage, fealty,
      or any other service than that mentioned in the feoffment;
      an estate in fee simple, subject to a perpetual rent.
      --Blackstone.

   Fee farm rent (Eng. Law), a perpetual rent reserved upon a
      conveyance in fee simple.

   Fee fund (Scot. Law), certain court dues out of which the
      clerks and other court officers are paid.

   Fee simple (Law), an absolute fee; a fee without conditions
      or limits.
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            Buy the fee simple of my life for an hour and a
            quarter.                              --Shak.

   Fee tail (Law), an estate of inheritance, limited and
      restrained to some particular heirs. --Burill.
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WordNet (r) 3.0 (2006):

fee simple
    n 1: a fee without limitation to any class of heirs; they can
         sell it or give it away

Moby Thesaurus II by Grady Ward, 1.0:

80 Moby Thesaurus words for "fee simple":
   adverse possession, alodium, burgage, claim, colony, copyhold,
   de facto, de jure, dependency, derivative title, equitable estate,
   estate at sufferance, estate for life, estate for years,
   estate in expectancy, estate in fee, estate in possession,
   estate tail, fee, fee fief, fee position, fee simple absolute,
   fee simple conditional, fee simple defeasible,
   fee simple determinable, fee tail, feod, feodum, feud,
   feudal estate, fief, fiefdom, frankalmoign, free socage, freehold,
   gavelkind, having title to, hold, holding, knight service, lay fee,
   lease, leasehold, legal claim, legal estate, legal possession,
   mandate, occupancy, occupation, original title, owning,
   paramount estate, particular estate, possessing, possession,
   preoccupancy, preoccupation, prepossession, prescription, property,
   property rights, proprietary rights, remainder, reversion, seisin,
   socage, squatting, sublease, tenancy, tenantry, tenure,
   tenure in chivalry, title, underlease, undertenancy, usucapion,
   vested estate, villein socage, villeinhold, villenage