zip code

¹

Or ZIP code,

noun

1. a system used in the U.S. to facilitate the delivery of mail, consisting of a five- or nine-digit code printed directly after the address, the first five digits initial code indicating the state and post office or postal zone, the last four expanded code the box section or number, portion of a rural route, building, or other specific delivery location.

zip-code

²

Or ZIP-code,

[zip-kohd]

verb (used with object)

zip-coded, zip-coding 

1. to provide or mark with a zip code.

   Zip-code all mail.

zip code

noun

1. the US equivalent of postcode

Word History and Origins

Origin of zip code¹

An Americanism first recorded in 1960–65, Z(one) I(mprovement) P(rogram)

Word History and Origins

Origin of zip code¹

C20: from z ( one ) i ( mprovement ) p ( lan )