English▸ noun an intense and widely shared enthusiasm for something, especially one that is short-lived; a craze:
younger children usually desire the latest fad that they'll probably soon lose interest in
[as modifier] I'm not one of those people who follows fad diets.
▪ an arbitrary and specific like or dislike, especially about food:
his fads about the type of coffee he must have.
– ORIGIN mid 19th century (originally dialect): probably the second element of fidfad, contraction of fiddle-faddle. Compare with faddy.