perusprismatiivinen
Perusprismatiivinen is a Finnish adjective that appears to be a neologism or a non-standard term, formed from perus (“basic, fundamental”) and prismatiivinen (“prismatic-like”). It is not a widely recognized or formally defined term in established Finnish mathematical vocabulary, and there is no consensus translation or fixed definition in English-language geometry.
Because perusprismatiivinen is not standard, its exact meaning can vary by author or context. In a teaching
Related, more established terms in Finnish include prisma for prism and prismamainen or prismaattinen as standard
See also: geometry, prisma, prismatoid, Finnish mathematical terminology.
References: no widely cited definition available; rely on the specific text where the term is used.