holdback vs reservation

holdback

noun
  • restraint (act or result of holding back, device that restrains) 

  • The projection or loop, on the thill of a vehicle, to which a strap of the harness is attached, to hold back a carriage when going downhill, or in backing. 

  • The strap or part of the harness so used. 

reservation

noun
  • The act of reserving, withholding or keeping back. 

  • The area which separates opposing lanes of traffic on a divided motorway or dual carriageway; see also central reservation. 

  • The practice of reserving part of the consecrated bread of the Eucharist for the communion of the sick. 

  • Something that is withheld or kept back. 

  • A limiting qualification regarding certainty; a doubt. 

  • An arrangement by which accommodation or transport arrangements are secured in advance. 

  • A power of an overseeing authority to suspend legislation in the jurisdiction being overseen pending the approval of a higher authority. Such as a provincial/state governor reserving a bill passed by the state/provincial legislature from assent, pending approval of the federal government; or a federal bill passed by federal parliament being reserved by the viceroy pending approval by the crown. 

  • A tract of land set apart by the US government for the use of a Native American people; Indian reservation (compare Canadian reserve). 

  • The act of the pope to reserve to himself the right to nominate to certain benefices. 

  • The setting aside of a certain percentage of vacancies in government institutions for members of backward and underrepresented communities (defined primarily by caste and tribe). 

How often have the words holdback and reservation occurred in a corpus of books? (source: Google Ngram Viewer )