Reservation /(r?z`?r-v?"sh?n)/

Res·er·va·tion

Reservation

n.
  1. The act of reserving, or keeping back; concealment, or withholding from disclosure; reserve.
    With reservation of an hundred knights.
    Make some reservation of your wrongs.
  2. Something withheld, either not expressed or disclosed, or not given up or brought forward.
  3. A tract of the public land reserved for some special use, as for schools, for the use of Indians, etc. [U.S.]
  4. The state of being reserved, or kept in store.
  5. A clause in an instrument by which some new thing is reserved out of the thing granted, and not in esse before. (Law)
  6. The portion of the sacramental elements reserved for purposes of devotion and for the communion of the absent and sick. (Eccl.)
  7. an agreement to have some space, service or other acommodation, as at a hotel, a restaurant, or on a public transport system, held for one's future use; also, the record or receipt for such an agreement, or the contractual obligation to retain that accommodation; as, a hotel reservation; a reservation on a flight to Dallas; to book a reservation at the Ritz.

Phrases & Compounds
Mental reservation
the withholding, or failing to disclose, something that affects a statement, promise, etc., and which, if disclosed, would materially change its import.