The Collaborative International Dictionary of English v.0.48:

Demise \De*mise"\, n. [F. d['e]mettre, p. p. d['e]mis,
   d['e]mise, to put away, lay down; pref. d['e]- (L. de or
   dis-) + mettre to put, place, lay, fr. L. mittere to send.
   See Mission, and cf. Dismiss, Demit.]
   1. Transmission by formal act or conveyance to an heir or
      successor; transference; especially, the transfer or
      transmission of the crown or royal authority to a
      successor.
      [1913 Webster]

   2. The decease of a royal or princely person; hence, also,
      the death of any illustrious person.
      [1913 Webster]

            After the demise of the Queen [of George II.], in
            1737, they [drawing- rooms] were held but twice a
            week.                                 --P.
                                                  Cunningham.
      [1913 Webster]

   3. (Law) The conveyance or transfer of an estate, either in
      fee for life or for years, most commonly the latter.
      --Bouvier.
      [1913 Webster]

   Note: The demise of the crown is a transfer of the crown,
         royal authority, or kingdom, to a successor. Thus, when
         Edward IV. was driven from his throne for a few months
         by the house of Lancaster, this temporary transfer of
         his dignity was called a demise. Thus the natural death
         of a king or queen came to be denominated a demise, as
         by that event the crown is transferred to a successor.
         --Blackstone.
         [1913 Webster]

   Demise and redemise, a conveyance where there are mutual
      leases made from one to another of the same land, or
      something out of it.

   Syn: Death; decease; departure. See Death.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Demise \De*mise"\, v. t. [imp. & p. p. Demised; p. pr. & vb.
   n. Demising.]
   1. To transfer or transmit by succession or inheritance; to
      grant or bestow by will; to bequeath. "Power to demise my
      lands." --Swift.
      [1913 Webster]

            What honor
            Canst thou demise to any child of mine? --Shak.
      [1913 Webster]

   2. To convey; to give. [R.]
      [1913 Webster]

            His soul is at his conception demised to him.
                                                  --Hammond.
      [1913 Webster]

   3. (Law) To convey, as an estate, by lease; to lease.
      [1913 Webster]

WordNet (r) 3.0 (2006):

demise
    n 1: the time when something ends; "it was the death of all his
         plans"; "a dying of old hopes" [syn: death, dying,
         demise] [ant: birth]
    v 1: transfer by a lease or by a will

Moby Thesaurus II by Grady Ward, 1.0:

100 Moby Thesaurus words for "demise":
   abalienation, alienation, amortization, amortizement, annihilation,
   assignation, assignment, bane, bargain and sale, barter,
   bequeathal, biological death, cash in, cessation of life, cession,
   clinical death, conferment, conferral, consignation, consignment,
   conveyance, conveyancing, crossing the bar, curtains, death,
   death knell, debt of nature, decease, deeding, deliverance,
   delivery, depart, departure, die, disposal, disposition,
   dissolution, doom, drop, dying, ebb of life, end, end of life,
   ending, enfeoffment, eternal rest, exchange, exit, expiration,
   expire, extinction, extinguishment, final summons, finger of death,
   giving, go, going, going off, grave, hand of death, jaws of death,
   knell, last debt, last muster, last rest, last roundup, last sleep,
   lease and release, leaving life, loss of life, making an end,
   parting, pass, pass away, passing, passing away, passing over,
   perishing, quietus, release, rest, reward, sale, sentence of death,
   settlement, settling, shades of death, shadow of death, silence,
   sleep, somatic death, succumb, summons of death, surrender,
   trading, transfer, transference, transmission, transmittal,
   vesting



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

DEMISE, persons. A term nearly synonymous with death. It is usually applied
in England to the death of the king or queen.



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

DEMISE, contracts. In its most extended signification, it is a conveyance
either in fee, for life, or for years. In its more technical meaning, it is
a lease or conveyance for a term of years. Vide Cow. L. & T. Index, h.t.;
Ad. Eject. Index, h.t.; 2 Hill. Ab. 130; Com. Dig. h.t., and the heads
there referred to. According to Chief Justice Gibson, the term demise
strictly denotes a posthumous grant, and no more. 5 1 Whart. R. 278. See 4
Bing. N. C. 678; S. C. 33 Eng. C. L. R. 492; 2 Bouv. Inst. n. 1774, et seq.