0 a wooden device that when turned round and round produces a noise like a series of knocks, traditionally used during the Jewish festival of Purim:
Groggers, or noisemakers, are used in the synagogue during the reading of Megillat Esther on Purim, whenever the name of the wicked "Haman" is mentioned.
We make so much noise with groggers that nobody can hear that hated name.