Kitniyot is the Hebrew term for legumes and certain grains or seeds avoided by many Ashkenazi Jews on Passover.
The word literally means “small things,” and its Passover meaning is broader than legumes alone. Depending on community and custom, kitniyot can include rice, corn, beans, peas, lentils, soy, peanuts, sunflower seeds, and sesame. These foods are generally not chametz under the Torah’s definition, which concerns leavened products made from wheat, barley, spelt, oats, or rye.
The custom of avoiding kitniyot developed among medieval Ashkenazi communities, especially in northern France, Provence, and the Rhineland. Proposed reasons include the risk of grain accidentally mixing with legumes, similarities in processing, and uncertainty about which foods might ferment. The original rationale is not certain, and the practice remains a minhag rather than a universal biblical prohibition.
This is why Passover food rules differ by Jewish community. Many Ashkenazi Jews avoid kitniyot, while many Sephardi and Mizrahi Jews traditionally eat them. Modern Reform and some Conservative authorities also permit them, so the term names a custom with varied observance rather than a universally forbidden food category.