ABSTRACT
ZIP code (daily life) A number used by the US Postal Service to help in mail sorting and delivery. In an address, it follows the names of the city and STATE. It consists of five digits (e.g., 12345) or nine digits (e.g., 12345–6789). In general, these numbers increase from east to west; they are lowest in Massachusetts (01000) and highest in Alaska (99500). [Acronym from the initials ‘Z’one ‘I’mprovement ‘P’lan.] Also spelled “zip”.
