To overvalue something, often a cost or rate of exchange, means to fix its value at too high a level compared with other similar things. a rate which does not overvalue the pound Many, perhaps all, Internet stocks are hugely overvalued. undervalue + overvaluation over·valu·ation These problems were aggravated by the overvaluation of the pound. + overvalued over·valued It still can be argued that Japanese shares are overvalued in terms of the return they offer. undervalued. to believe or say that something is more valuable or more important than it really is