established vs revocable

established

adj
  • Explicitly defined, described or recognized as a reference. 

  • Of a religion, church etc.: formally recognized by a state as being official within that area. 

  • Having been in existence for a long time and therefore recognized and generally accepted. 

revocable

adj
  • Having the ability of being revoked; capable of being revoked. 

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