trigésima

Trigésima is the feminine form of the Spanish ordinal numeral that denotes the thirtieth position or order. It agrees with feminine nouns, while the masculine form is trigésimo and the plural forms are trigésimos (masculine) and trigésimas (feminine). The feminine ending is used when the noun it modifies is feminine, as in la trigésima edición or la trigésima parte.

In usage, trigésima functions as an ordinal adjective and can also appear as a noun in fixed expressions. Common examples include la trigésima página, la trigésima edición, or una trigésima parte del total. In lists or sequences, it is typical to encounter la trigésima posición de un ranking or la trigésima entrega de una colección, always matching the gender of the noun that follows. For arithmetic or fractions, the related noun un trigésimo (or su plural trigésimos) is used to mean one thirtieth.

Etymologically, trigésima derives from the Latin trigesimus, formed from triginta meaning thirty, with the Spanish -ésimo suffix that marks ordinal numbers. The form trigésima reflects standard Spanish gender and number agreement rules for adjectives and nouns in feminine singular contexts.

See also: trigésimo, trigésimas, trigésimos, ordinal numbers in Spanish, fractions such as trigésimo.

Notes: While trigésima appears frequently in formal or written Spanish—such as academic, legal, or literary contexts—it is less common in everyday speech when the exact ordinal is not required. In numerical sequences, dates, or editions where a feminine noun is present, trigésima is routinely used.