What is the definition of reservation?

The act of reserving, or keeping back; concealment, or withholding from disclosure; reserve., Something withheld, either not expressed or disclosed, or not given up or brought forward., A tract of the public land reserved for some special use, as for schools, for the use of Indians, etc., The state of being reserved, or kept in store., A clause in an instrument by which some new thing is reserved out of the thing granted, and not in esse before., A proviso., The portion of the sacramental elements reserved for purposes of devotion and for the communion of the absent and sick., A term of canon law, which signifies that the pope reserves to himself appointment to certain benefices.