Retrenchment was the word used in Jane Austen’s time to describe the act of cutting back financially. For example:

In “Persuasion”:

She consulted, and in a degree was influenced by her in marking out the scheme of retrenchment which was at last submitted to Sir Walter.

In “Mansfield Park”:

"Lady Bertram, I do not complain. I know I cannot live as I have done, but I must retrench where I can, and learn to be a better manager. I have been a liberal housekeeper enough, but I shall not be ashamed to practise economy now.”