sejm

Polish sejm meant an assembly, a gathering called to deliberate or decide. The word is attested in medieval and early modern Polish political life, and by the sixteenth century it named the parliament of the Polish-Lithuanian Commonwealth. This was not a decorative institution. It could crown, tax, stall, and wreck a state.

The form barely changed because English borrowed it as a constitutional term rather than a household word. Foreign observers kept the Polish spelling to signal that the thing itself was specifically Polish and not quite the same as a parliament in Westminster or Paris. Precision was part of the exoticism.

The word circulated in diplomatic reports, histories of the Commonwealth, and later modern coverage of Poland's legislature. After the partitions of Poland, sejm became a word tied to memory as much as government. Institutions can vanish. Their names become political claims.

Modern Sejm is the lower house of the Polish parliament. English still keeps the Polish form, capitalized when it means the modern body. Some political words resist translation because they have paid too much for survival.