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: --
We make so much noise with groggers that nobody can hear that hated name.
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.