plakkeihin

Plakkeihin is the illative plural form of the Finnish noun plakki. Plakki has several related meanings that all connect with a flat surface or layer: in everyday language it can refer to a dental plaque (a biofilm on teeth), and more broadly to a flat plate, sign or label that bears information. In that broader sense, plakki can denote a physical plaque or panel used for inscriptions or identification. Plakkeihin is used when speaking about movement toward or placement onto multiple such plaques.

In practice, the sense most familiar to many speakers is the literal plate or plaque that carries names, dates or other information, such as a commemorative or informational plaque on a wall or display. The dental sense, while common, is typically discussed with the noun plakki in its singular or plural forms appropriate to quantity (for example plakkia or plakkia in various grammatical cases), whereas plakkeihin appears when the speaker explicitly refers to several plaques in illative mood. Through its figurative and material uses, plakki and its inflected forms share the idea of a flat surface that can bear text or a coating on a surface.

Usage notes: plakkeihin is a niche form tied to plural plaques and movement toward them. In many contexts, other terms such as plaketti or muistotaulu are preferred for a single information plaque, while the dental sense is usually described with plakki in the appropriate case. See also plaque in English and its Finnish equivalents.