from
The Collaborative International Dictionary of English v.0.48
Porism \Po"rism\, n. [Gr. ? a thing procured, a deduction from a
demonstration, fr. ? to bring, provide: cf. F. porisme.]
1. (Geom.) A proposition affirming the possibility of finding
such conditions as will render a certain determinate
problem indeterminate or capable of innumerable solutions.
--Playfair.
[1913 Webster]
2. (Gr. Geom.) A corollary. --Brande & C.
[1913 Webster]
Note: Three books of porisms of Euclid have been lost, but
several attempts to determine the nature of these
propositions and to restore them have been made by
modern geometers.
[1913 Webster] Porismatic