gravy plane
n.— «Now, however, the gravy plane has been grounded. As a result of the reporters’ questions, City Manager Frank Fairbanks has decided that the city ought to actually put some limits on city junketeers.» —“Dig deeper to help Phoenix junketless this holiday season” by Laurie Roberts Arizona Republic (Phoenix) Nov. 30, 2005. (source: Double-Tongued Dictionary)
Further reading
Is there such a thing as a “neutral” accent, and if so what does it sound like? And that quirk in the way southern Californians talk about freeways. They’ll say things like take the 405 and get on the 8. Why the definite article...
Why do southern Californians refer to interstate thoroughfares with the definite article, as in the 405 or the 8? This usage is a result of the history of freeways in Southern California, and is heard in a few other places, including Phoenix...