dependency vs protectorate

dependency

noun
  • A colony, or a territory subject to rule by an external power. 

  • Reliance on the functionality provided by some other, external component. 

  • A state of dependence; a refusal to exercise initiative. 

  • An external component whose functionality is relied on. 

  • Something dependent on, or subordinate to, something else 

  • A dependence on a habit-forming substance such as a drug or alcohol. 

protectorate

noun
  • The authority assumed by a superior power over an inferior or a dependent one, whereby the former protects the latter from invasion and shares in the management of its affairs but the protected state retains its nominal sovereignty. 

  • An autonomous territory that is protected diplomatically or militarily against third parties by a stronger state or entity. 

  • Government by a protector; especially, the government of England, Scotland, and Ireland by Oliver Cromwell. 

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