Kokoikäisen

Kokoikäisen is a Finnish term formed from koko (whole, full) and ikäinen (age-related). It functions as an adjective meaning “of full age” or “adult.” In practice, the expression is less common in everyday speech, where täysi-ikäinen is the standard term for legal adulthood. Kokoikäinen often conveys maturity or full development more than legal status and can be found in more formal, technical, or literary contexts.

Etymology and usage notes: The word derives from the combination of koko and ikäinen, emphasizing completeness of age. When used in sentences, kokoikäinen follows normal Finnish adjective agreement, and its genitive singular form is kokoikäisen. This form appears when the adjective modifies a noun in the genitive, for example kokoikäisen henkilön oikeudet (“the rights of an adult person”) or kokoikäisen kissan ruokavalio (“the diet of an adult cat”).

Relation to other terms: The most common term for legal adulthood is täysi-ikäinen. Aikuinen is another general word for “adult,” often emphasizing status or maturity rather than legal age. Kokoikäinen can also be used to describe animals or organisms that have reached full growth, rather than focusing on legal age.

Nuance and register: Kokoikäinen is more likely to appear in formal, scientific, or descriptive writing. It may be used to highlight maturation or growth stages, or to contrast with underage or immature states.

Examples: kokoikäisen kissan ruokavalio; kokoikäisen henkilön oikeudet. In everyday language, you are more likely to encounter muita: täysi-ikäinen henkilö or aikuinen.