apostasy

Noun

apostasy (countable and uncountable, plural apostasies)

1. The renunciation of a belief or set of beliefs.
   • The apparition of Lawyer Clippurse at the Hall occasioned much speculation in that portion of the world to which Waverley-Honour formed the centre: but the more judicious politicians of this microcosm augured yet worse consequences to Richard Waverley from a movement which shortly followed his...1814 July 7, [Walter Scott], chapter II, in Waverley; or, ’Tis Sixty Years Since. […], volume (please specify |volume=I to III), Edinburgh: […] James Ballantyne and Co. for Archibald Constable and...
   • The King of Navarre suddenly abandoned his party and went over to the Catholics. The explanation of his apostasy was as simple as it was base: Navarre had no confidence in the success of his cause, and he cared little in his heart for anything but women and vanity.1856–1870, James Anthony Froude, History of England from the Fall of Wolsey to the Death of Elizabeth, volume (please specify |volume=I to XII), London: Longmans, Green, and Co., →OCLC, page 394

   Synonyms:

   backsliding[emic]] viewpoint only>

2. Specifically, the renunciation of one's religion or faith.

   Synonyms:

   defection, disaffection, estrangement