zip code


zip code

noun, often capitalized Z&I&P

: a group of numbers that is used in the U.S. as part of an address to identify a mail delivery area (such as a town or a part of a city)

Full Definition of ZIP CODE

:  a number that identifies a particular postal delivery area in the United States
:  the geographic area identified by a zip code

Origin of ZIP CODE

zone improvement plan
First Known Use: 1963

zip code

noun    (Concise Encyclopedia)

System of postal-zone codes (zip stands for “zone improvement plan”) introduced in the U.S. in 1963 to improve mail delivery and exploit electronic reading and sorting capabilities. The original code, which corresponds to the postal codes used in most countries in the world, consists of five numbers. The first three identify the state and portion of the state, the last two a specific post office or zone. In 1983 a nine-digit code (created by adding a hyphen and four digits) was introduced to further speed delivery; the first two added digits specify a particular “sector,” the last two an even smaller “segment” (e.g., one side of a city block, or a single floor in a large building).


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