n. 1. the relationship between two numbers, quantities, etc. that holds when they are comparable but not equal, so that they are related by a strict ordering. 2. a statement that such a relation holds; the negation of an equality or equation, written a ≠ b. 3. any of the specific relationships:
a < b (a is less than b),
a ≤ b (a is less than or equal to b),
a > b (a is greater than b), or
a ≥ b (a is greater than or equal to b).