The Collaborative International Dictionary of English v.0.48:

Tenancy \Ten"an*cy\, n.; pl. Tenacies. [Cf. OF. tenace, LL.
   tenentia. See Tenant.] (Law)
   (a) A holding, or a mode of holding, an estate; tenure; the
       temporary possession of what belongs to another.
   (b) (O. Eng. Law) A house for habitation, or place to live
       in, held of another. --Blount. Blackstone. Wharton.
       [1913 Webster]

WordNet (r) 3.0 (2006):

tenancy
    n 1: an act of being a tenant or occupant [syn: occupancy,
         tenancy]

Moby Thesaurus II by Grady Ward, 1.0:

81 Moby Thesaurus words for "tenancy":
   abiding, abode, adverse possession, alodium, burgage, claim,
   cohabitation, colony, commorancy, de facto, de jure, dependency,
   derivative title, dwelling, fee fief, fee position, fee simple,
   fee simple absolute, fee simple conditional, fee simple defeasible,
   fee simple determinable, fee tail, feodum, feud, fiefdom,
   frankalmoign, free socage, freehold, gavelkind, habitancy,
   habitation, having title to, hold, holding, inhabitancy,
   inhabitation, inhabiting, knight service, lay fee, lease,
   leasehold, legal claim, legal possession, living, lodging, mandate,
   nesting, occupancy, occupation, original title, owning, possessing,
   possession, preoccupancy, preoccupation, prepossession,
   prescription, property, property rights, proprietary rights,
   residence, residency, residing, seisin, socage, sojourning,
   squatting, staying, staying over, stopping, sublease, tenantry,
   tenure, tenure in chivalry, title, underlease, undertenancy,
   usucapion, villein socage, villeinhold, villenage



Bouvier's Law Dictionary, Revised 6th Ed (1856):

TENANCY or TENANTCY. The state or condition of a tenant; the estate held by
a tenant, as a tenant at will, a tenancy for years.