sentinel vs ward

sentinel

verb
  • To watch over as a guard. 

  • To post as guard. 

  • To post a guard for. 

noun
  • A unique string of characters recognised by a computer program for processing in a special way; a keyword. 

  • A sentry, watch, or guard. 

  • A sentinel crab. 

  • A sign of a health risk (e.g. a disease, an adverse effect). 

ward

verb
  • To keep in safety, to watch over, to guard. 

  • To defend, to protect. 

  • To be vigilant; to keep guard. 

  • To fend off, to repel, to turn aside, as anything mischievous that approaches (usually followed by off) 

  • To act on the defensive with a weapon. 

noun
  • The ridges on the inside of a lock, or the incisions on a key. 

  • The action of a watchman; monitoring, surveillance (usually in phrases keep ward etc.) 

  • An object used for guarding. 

  • A subdivision of the LDS Church, smaller than and part of a stake, but larger than a branch. 

  • A part of a hospital, with beds, where patients reside. 

  • A section or subdivision of a prison. 

  • An enchantment or spell placed over a designated area or social unit, that prevents any tresspasser from entering; approaching; or even being able to locate said protected premises or demographic. 

  • A guarding or defensive motion or position. 

  • Land tenure through military service. 

  • Guardianship, especially of a child or prisoner. 

  • A warden; a guard; a guardian or watchman. 

  • An area of a castle, corresponding to a circuit of the walls. 

  • An administrative division of a borough, city or council. 

  • A minor looked after by a guardian. 

  • A division of a forest. 

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