The Collaborative International Dictionary
Persism \Per"sism\, n. A Persian idiom.
Persism \Per"sism\, n. Ancient Persian religion, esp. as represented by the Magi.
This system we shall call 'Persism', in order to free
ourselves of the popular associations still connected
with such terms as magism, Parseeism, and so forth;
meaning by 'Persism' the teaching of Zarathustra as it
affected the Greek and Latin world.
--E. Vernon Arnold.