These words mean to give unlike characteristics or appearances to the members of a group of things. To diversify one’s reading is to read about a number of different subjects; to diversify one’s business is to embark on different kinds of commercial enterprises.

To vary is to make different the successive elements of a series of related things. To vary one’s diet is to eat different kinds of food at successive meals; to vary one’s work routine is to break up one’s day into segments devoted to various aspects of one’s job rather than to concentrate on one aspect of it over a long period of time.

To variegate is to impart variety to a group of similar things by giving them different colours, shapes, sizes, and the like. Easter eggs are variegated by colouring, bouquets by arrangement, book by jacked design or choice of type.