Wikipedia
Kitniyot
Kitniyot, (, qit'niyyot) (legumes) is a Hebrew word meaning legumes. During the Passover holiday, the word kitniyot takes on a broader meaning to include the category of foods that may not be eaten during Passover by Jews following traditional Ashkenazi laws and customs. Long-standing tradition in other communities and recent rulings have given support in certain cases for variation from this practice.
Kitniyot according to the Passover tradition includes legumes, but also grains and seeds. Examples include rice, corn, sunflower seeds, sesame seeds, soy beans, peas, and lentils.