Definition of "purgatory"

[…] many Gods breedeth heathens miseries, many countries trauailers humors, many wiues mens purgatories, and many friends trustes ruine:

1605, Nicholas Breton, An Olde Mans Lesson, and a Young Mans Loue‎, London: Edward White

I laid my rank and fortune at the fair one’s feet, and would have married instantly; but that Oldworth opposed my precipitancy, and insisted upon a probation of six months absence—It has been a purgatory!

1774, John Burgoyne, The Maid of the Oaks‎, London: T. Becket, act I, scene 1, page 6

It might be […] that Ruth had worked her way through the deep purgatory of repentance up to something like purity again; God only knew!

1853, Elizabeth Gaskell, chapter 25, in Ruth‎

Later came midsummer, with the stifling heat, when the dingy killing beds of Durham’s became a very purgatory; one time, in a single day, three men fell dead from sunstroke.

1904, Upton Sinclair, chapter 10, in The Jungle‎

[…] that would mean he would be irrecoverably Afrikaans and would have to spend years in the purgatory of an Afrikaans boarding-school, as all farm-children do, before he would be allowed to come back to the farm.

1997, J. M. Coetzee, chapter 11, in Boyhood: Scenes from Provincial Life‎, Penguin, page 100

Last of all, the prodigie of Siracusa was expiat by a purgatory sacrifice, by direction from the soothsaiers to what gods, supplications and sacrifice should be made.

1600, Philemon Holland, transl., The Roman Historie Written by T. Livius of Padua‎, London, Book 41, p. 1103

This purgatory interval is not unfavourable to a faithless representative, who may be as good a canvasser as he was a bad governor.

1790, Edmund Burke, Reflections on the Revolution in France‎, London: J. Dodsley, page 272