Which integer is greatest

Greatest Integer Function [X] indicates an integral part of the real number which is nearest and smaller integer to. Definition of the greatest integer function and graph. The greatest integer function f(x) = [x] is the greatest integer less or equal to x. IN MATH: 1. n. the function, or rule which produces the "greatest integer less than or equal to the number" operated upon, symbol [x] or sometimes [[x]].