Tympf

The Tympf (rarely Timpf, Polish: tymf or tynf[1]) was a low-grade silver coin used in Poland-Lithuania, Brandenburg-Prussia, and Russia in the 17th and 18th centuries.

[5] After the Electors of Saxony took over the Polish royal crown in 1688, many tympfe in the Leipzig mint were struck as 18-groschen pieces.

The Prussian King Frederick II, who had conquered the city in the Seven Years' War, discontinued minting in 1765.

There is a saying: Dobry żart tymfa wart (A good joke is worth a tympf).

with N. Bauer, K. Regling, A. Suhle, R. Vasmer, J. Wilcke: Dictionary of numismatics.