Green’s Dictionary of Slang

1. (US) the élite residents of New York City.

1854		Yazoo Democrat (MS) 31 May 1/2: A sublimated, snobbish squirt — a genuine Fifth-Avenoodle.
1858		‘Ned Buntline’ Shell-Hunter 4: [...] Fifth-avenoodles of the present day, as men are from monkey.
1859		J.W. Palmer New and the Old 90: [He] had sent him hither to induct us outside-barbarian Fifth-Avenoodles in the refinements and intricacies of celestial etiquette.
1860		D.R. Hundley Social Relations in Our Southern States 235: New-York saloon-keepers are so loud in their praises of those youthful Fifth-Avenoodles, who are wasting their patrimony in such hot haste by means of their fast horses.
1874		A.A. Hopkins Asleep in the Sanctum 3: Of the leaders of ton the be-gemmed avenoodles / Who’re proud of their purses, in love with their poodles.
1882		C.G. Leland Gypsies 211: He agrees with the Chinese, red Indians, May Fairies, and Fifth Avenoodles.
1895		Sun (NY) 15 June 6/4: Many of our Fifth Avenue people, once known as Fifth Avenoodles, were out of town.
1951		L.R. Morris Incredible N.Y. 17: New York society was not taking its tone from the ‘Fifth Avenue Noodles,’ or ‘avenoodles,’ as they were called.
1993		(ref. to 1850s) I.L. Allen City in Sl. (1995) 221: The long forgotten [...] slang name for residents of the street, Fifth Avenoodles, or just Avenoodles, appeared by the 1850s.

2. as used of other cities.

1864

[J. Barber] War letters of a Disbanded Volunteer 113: I ken oney say they air kwoted as reglar Lincoln callembores by all the Penuselvany Avenoodles.