The Collaborative International Dictionary of English v.0.48:

Preservation \Pres`er*va"tion\, n. [Cf. F. pr['e]servation.]
   The act or process of preserving, or keeping safe; the state
   of being preserved, or kept from injury, destruction, or
   decay; security; safety; as, preservation of life, fruit,
   game, etc.; a picture in good preservation.
   [1913 Webster]

         Give us particulars of thy preservation. --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

preservation
    n 1: the activity of protecting something from loss or danger
         [syn: preservation, saving]
    2: the condition of being (well or ill) preserved
    3: a process that saves organic substances from decay
    4: an occurrence of improvement by virtue of preventing loss or
       injury or other change [syn: conservation, preservation]

Moby Thesaurus II by Grady Ward, 1.0:

67 Moby Thesaurus words for "preservation":
   bottling up, care, cold storage, conservancy, conservation,
   continuation, corking up, cover, creation, custody, dead storage,
   defense, dispensation, dry storage, eternal re-creation,
   eternal return, eternalization, eye, guard, guardianship, holding,
   holding in, immortalization, inhibition, keeping, lee, locking in,
   maintenance, perpetuating, perpetuation, prehension, preserval,
   protecting, protection, protective custody, providence, refuge,
   repression, retaining, retainment, retention, retentiveness,
   retentivity, safeguard, safeguarding, safekeeping, safety,
   salvation, saving, security, shade, shadow, shelf-room, shelter,
   shield, steady-state universe, storage, storage space, stowage,
   suppression, sustentation, tenacity, upkeep,
   visitations of providence, ward, warehousing, watchful eye



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

PRESERVATION. keeping safe from harm; avoiding injury. This term always
presupposes a real or existing danger.
     2. A jettison, which is always for the preservation of the remainder of
the cargo, must therefore be made only when there is a real danger existing.
See Average; Jettison.