Definition of porism in English:


Pronunciation /ˈpɔːrɪz(ə)m/ /ˈpɒrɪz(ə)m/


  • In Euclidean geometry: a proposition arising during the investigation of some other proposition by immediate deduction from it; (in later use) a special case of a problem in which the particular values of its parameters result in the solution being indeterminate.

    Other widely different definitions have also been given.


Late Middle English; earliest use found in Geoffrey Chaucer (c1340–1400), poet and administrator. From (i) post-classical Latin porisma a deduction, a corollary and its etymon (ii) Hellenistic Greek πόρισμα a deduction from a previous demonstration, a corollary (Euclid), a kind of proposition intermediate between a theorem and a problem from ancient Greek πορίζειν to carry, to provide, in Hellenistic Greek also to find out (from πόρος way + -ίζειν) +-μα.