Definition of "extravagance"

The visions of romance were over. Catherine was completely awakened. Henry’s address, short as it had been, had more thoroughly opened her eyes to the extravagance of her late fancies than all their several disappointments had done.

1803, Jane Austen, Northanger Abbey

A great bargain also had been the excellent Axminster carpet which covered the floor; as, again, the arm-chair in which Bunting now sat forward, staring into the dull, small fire. In fact, that arm-chair had been an extravagance of Mrs. Bunting. She had wanted her husband to be comfortable after the day's work was done, and she had paid thirty-seven shillings for the chair.

1913, Mrs. [Marie] Belloc Lowndes, chapter I, in The Lodger, London: Methuen; republished in Novels of Mystery: The Lodger; The Story of Ivy; What Really Happened, New York, N.Y.: Longmans, Green and Co., […], page 0016