Learn how to say Faddist correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word fad:
an intense and widely shared enthusiasm for something, especially one that is short-lived; a craze:
some regard green politics as no more than the latest fad
an arbitrary like or dislike:
his fads about the type of coffee he must have
mid 19th century (originally dialect): probably the second element of fidfad, contraction of fiddle-faddle. Compare with faddy