desecrate

It's reform -- reform! You're going to 'turn over a new leaf,' and all that, and sign the pledge, and quit cigars, and go to work, and pay your debts, and gravitate back into Sunday-school, where you can make love to the preacher's daughter under the guise of religion, and desecrate the sanctity of the innermost pale of the church by confessions at Class of your 'thorough conversion'!

A subsequent owner has desecrated the main hall and robbed it of its grandeur by putting in a floor just beneath the circular windows in order to make an upper room over the hall.