osiemnastowiecznej

Osiemnastowiecznej is the feminine singular form of the Polish adjective osi emnastowieczny, meaning relating to the eighteenth century or from the eighteenth century. It is used with feminine nouns and appears in various grammatical cases, most commonly as genitive, dative, or locative. The form is typically found in descriptive phrases such as osi emnastowiecznej architekturze (in eighteenth‑century architecture) or osi emnastowiecznej literaturze (in eighteenth‑century literature).

The base term originates from the numeral for eighteen, combined with the productive adjectival suffix -owieczny, which in Polish forms time‑period adjectives. In historiography and description, this adjective describes cultural, political, and social phenomena of the region during roughly 1700–1799, including the late Polish–Lithuanian Commonwealth and the era leading up to the partitions of Poland. The specific form osi emnastowiecznej surfaces when the accompanying noun is feminine and in one of the declined cases.

Because Polish adjectives agree with the nouns they modify, the feminine genitive singular form of osi emnastowieczny is osi emnastowiecznej, with other case forms existing for masculine, neuter, or plural nouns. The word is most commonly encountered in scholarly writing, historical prose, and discussions of eighteenth‑century culture, where precise grammatical agreement is essential for clear description.