[{"Bold_text": "noun", "List Items": ["Trigonometry.(in a right triangle) the ratio of the side adjacent to a given angle to the hypotenuse.the sine of the complement of a given angle or arc.:cos", "(in a right triangle) the ratio of the side adjacent to a given angle to the hypotenuse.", "the sine of the complement of a given angle or arc.:cos", "Mathematics.(of a real or complex numberx) the function cosxdefined by the infinite series 1 ? (x2/2!) + (x4/4!) ? + …, where ! denotes factorial.:cos Compare sine(def3) sine(def3), factorial(def1) factorial(def1)."]}]