- noun a logical way of writing mathematical operations, so that the operator appears after the operands, thus removing the need for brackets
- noun mathematical operations written in a logical way, so that the operator appears after the operands, which removes the need for brackets
- A manner of forming mathematical or logical expressions in which the operators appear after the operands. For example, (A + B) × C, which is in infix notation, would appear as ABC+* in postfix notation. Also called reverse Polish notation, or suffix notation.