yardstick - a evaluate or standard utilized for comparison; "on what sort of yardstick is he basing his judgment?"(the time of) the moon when it appears at its most finish. There is a total moon tonight. volmaan بَدِر пълнолуние lua cheia úplněk der Vollmond fuldmåne πανσέληνοςluna llena täiskuu قرص ماه täysikuu