peilinen

Peilinen is a Finnish adjective meaning mirror-like or reflective. It is formed from the noun peili "mirror" with the derivational suffix -nen, a productive pattern in Finnish that yields adjectives describing qualities. The term is relatively rare in everyday Finnish and is most often encountered in literary or descriptive prose where authors evoke imagery of glassy surfaces, reflections, or symmetry.

In use, peilinen describes both literal and figurative resemblance to a mirror. Literal: a surface that resembles a mirror, such as still water, polished metal, or a smooth pane that reflects. Figurative: something that presents or suggests a reflected image, or that invites introspection and doubling of identity, as in metaphorical phrasing.

The word can appear in noun phrases such as "peilinen vesi" or "peilinen pinta," though variants and synonyms are common in the national language. Related terms include peili (mirror) and peilikuva (mirror image) and heijastus (reflection). As a literary device, peilinen contributes to imagery of symmetry, duality, and perception, and is favored by writers seeking to evoke calm, stillness, or self-scrutiny.

Due to its literary character, peilinen is not a standard term in everyday conversation, and usage may seem archaic or stylistically marked outside specific genres or registers.