Lapseksi

Lapseksi is a translative form in Finnish derived from the noun lapsi, meaning child. In grammar, the translative case is used to express a change of state or designation, so lapseksi indicates becoming or acting as a child. The form is relatively rare in everyday language and is more commonly found in literary, historical, or formal contexts where authors want to emphasize a shift in identity or role.

Morphology and usage notes:

The singular form is lapseksi, and the plural form is lapseiksi. The translative expresses a transition, for example in phrases that describe someone taking on the status or role of a child, or in mythic or symbolic narration. In contemporary speech, speakers more often use other constructions to convey similar ideas, such as describing actions that involve children or discussing adulthood as a change of state rather than using the translative of lapsi.

Relation to other Finnish forms:

Lapsi is the base noun meaning child, and lapseksi belongs to the family of translative forms formed with the suffix -ksi. The translative can attach to many nouns to indicate becoming something, which makes lapseksi part of a wider grammatical pattern in Finnish for signaling transformations or new roles. In practice, lapseksi is just one specific instance of this pattern and is most readily encountered in texts that aim for a formal or stylistic nuance.

See also:

Finnish translative case, lapsi (child), Finnish morphology, grammatical cases in Finnish.

References:

Finnish language grammar resources on translative forms and noun inflection.