In linguistics, a paradigm is a set of systematically alternating items. For instance, the conjugation of a verb, or the declension of a noun, or the set of flags to the ls command. A paradigm is complementary to a syntagm, which is a set of items used in systematic combination.

Also used in philosophy to refer to a frame of mind or a frame of reference.

This word was made famous by Thomas Kuhn, when he argued that science works by establishing scientific paradigms, carrying out research in line with the paradigm, and finally, overthrowing the paradigm in favour of a newer one when too much evidence is assembled that doesn't fit.