Arizona

A room named for a state, built to dodge the heat that state is famous for.

Postwar builders in Phoenix and Tucson sold the shaded side room as a regional feature, and the name spread with the Sun Belt. The same idea is called a Florida room farther east, where the enemy is humidity and insects rather than sun.

Arizona became a slang prefix meaning the cheapest possible version of anything.

Green's Dictionary of Slang treats Arizona as a generic derogatory modifier and lists a run of ironic coinages under it: an Arizona cloudburst is a sandstorm, an Arizona nightingale a donkey, an Arizona strawberry a bean. Arizona perfume applies the same sarcasm to lethal gas. The state did execute prisoners with hydrogen cyanide from 1934, though no source ties the phrase directly to that.