The Collaborative International Dictionary of English v.0.48:

Rental \Rent"al\ (-al), n. [LL. rentale, fr. renta. See Rent
   income.]
   1. A schedule, account, or list of rents, with the names of
      the tenants, etc.; a rent roll.
      [1913 Webster]

   2. A sum total of rents; as, an estate that yields a rental
      of ten thousand dollars a year.
      [1913 Webster]

WordNet (r) 3.0 (2006):

rental
    adj 1: available to rent or lease; "a rental car"
    2: of or relating to rent; "rental agreement"; "rental charges"
    n 1: property that is leased or rented out or let [syn: lease,
         rental, letting]
    2: the act of paying for the use of something (as an apartment
       or house or car) [syn: rental, renting]

Moby Thesaurus II by Grady Ward, 1.0:

20 Moby Thesaurus words for "rental":
   bareboat charter, chambers, charter, flat, hire, hiring, lease,
   lend-lease, let, lodgings, quitrent, rack rent, rent, rent charge,
   rent-roll, rooms, sublease, subrent, suite, tenement