päänomini

Päänomini is a term used in Finnish linguistics to refer to the head noun of a noun phrase or compound. In many languages that form compounds, the head determines the core meaning and the grammatical behavior of the whole word or phrase. In Finnish, compounds are typically head-final: the rightmost element functions as the head, while the preceding elements provide semantic modifiers. The päänomini therefore has the main syntactic role and often carries the central meaning of the compound.

Because the head governs inflection, the entire compound is inflected as if it were the head noun. The modifier elements are commonly in the genitive when indicating relationships such as possession or composition, but the inflection of the whole word follows the head's case and number. This makes a päänomini essential for understanding how a compound fits into larger sentences.

Examples include kirjahylly (book shelf) with hylly as the head; opettajanhuone (teacher's room) with huone as the head; and koiranruoka (dog food) with ruoka as the head, where koiran denotes a possessive relationship. There are edge cases and exceptions, such as exocentric compounds or semantic shifts that affect which element is perceived as the head.

In broader linguistics, the concept of a head noun appears as part of noun-phrase structure and compound theory across languages. The term päänomini is primarily used in Finnish-language literature, though similar ideas exist in cross-linguistic typology for head-final and other types of compounds.

Related topics include compound word formation, noun phrase structure, and possessive constructions.