Green’s Dictionary of Slang

1. (US) a (usu. white, usu. poor) native of Arkansas, usu. as a migrant in another state; ext. to mean any yokel.

1927		H. Dignowity in Dobie Texas and Southwestern Lore 101: Men who are mentally sluggish [...] are quickly dubbed with such names as ‘Arkansas’ or ‘Arky’; men from that state seem to be considered defective or lacking in mental powers.
1945		C. Himes If He Hollers 92: I heard the manager saying to the Arky Jill, ‘You’ve got to go out with them’.
1955		E. Hoagland Cat Man 217: Yes, he was the Tennessee type, more than the hayseed Arkie.
1969		Oz 20 31/1: This 35 year old Arkie – he’s from Arkansas.
1979		‘Iceberg Slim’ Airtight Willie and Me 147: Crazy enough to hook up with an Arkie from the coal pits.
1990		S. Morgan Homeboy 152: This Arkie bohunk named Hutchinson actually [...] helped himself to some of that boy’s butthole.
2000		Arkansas Roadside Travelogue 1 Apr. 🌐 [heading] Arkies At War. [...] Pictured at left is the hometown monument of one of Arkansas’ greatest heroes, Herman Davis.
2006		First Measured Century [PBS-TV] Some of the rural Okies and Arkies faced deep-seated discrimination and scorn when they arrived in California.

2. (S.Afr.) a student of the university of Cape Town.

1972

‘Rawbone Malong’ Ah Big Yaws? 25: An annual rugby match played between the Arkies and the Morties (students of the Universities of Cape Town and Stellenbosch, respectively).