Kääntöinen

Kääntöinen is a Finnish term-form derived from the noun kääntö (turn, reversal) with the adjectival suffix -inen. In standard Finnish, it is not a widely used or clearly defined lexical item, and it does not have a fixed entry in major dictionaries. Because of its rarity, its meaning is highly context-dependent and largely undefined outside of specific texts.

In practice, kääntöinen tends to appear in specialized, historical, or dialectal contexts where it can be used to describe something that can be turned, inverted, or reversed, or to denote a property related to turning. However, there is no universally accepted definition, and standard Finnish terminology for “inverse” or “reverse” is typically expressed with words such as käänteinen or vastakkainen.

For mathematical or logical contexts, käänteinen is the conventional term for the inverse or inverse operation, and kääntöinen would be unusual. If encountered, it is advisable to check the surrounding text for a definition, as the intended meaning of kääntöinen can vary between authors and historical periods. Because of its limited and context-specific usage, kääntöinen is best treated as a rare or archaic form rather than a productive, everyday word.

See also: käänteinen, kääntö, kääntöpuoli, inversio.