Radikalinski.

Late 19th century, from radikal + -inski. The latter suffix was also used in some other formations (like Brutalinski), but Radikalinski is the commonest and perhaps original form. Derived from Slavic surnames, especially Polish -iński, -yński (as in Kaczyński, Kamiński, Zieliński, etc.). At the time there could have been an association with Polish nationalist revolutionaries, who were considered enemies of state in the German Empire. However, Slavic surnames have been fairly common in Germany (especially in eastern regions and the Ruhrgebiet), so there need not necessarily have been a particular ethnic or political association.