The crossword solution for the term 'single item' is UNIT, which is a four letter word. A UNIT is a single item or entity, usually used to refer to a single object or component of a larger system. It can also refer to a single person or group within a larger organization. Units are often used in measurements, such as a UNIT of length or a UNIT of time. In mathematics, a UNIT is a number that has no value other than itself.