deprecate or depreciate? The difference in meaning of these two words is being eroded. To deprecate is a rather formal verb meaning to ‘feel or express disapproval of (something)’: She deprecated their lack of courtesy toward the old lady. To depreciate means both to ‘fall in value’ or ‘lower the value of (something)’ (The currency is depreciating) and, more formally, to ‘belittle (somebody or something)’: My efforts were depreciated and I was made to feel useless. The distinction between expressing disapproval and belittling or disparaging is sometimes so fine that the words deprecate and depreciate are increasingly being used interchangeably