Green’s Dictionary of Slang

Oklahoma adj.

used in combs. pertaining to the state, usu. implying social and material backwardness.

In compounds

Oklahoma credit card (n.)

(US) a siphon tube for stealing gasoline.

[US]R. Hancock Baja California 65: Mike called this siphon hose an Oklahoma credit card.
[US]D. Dempsey ‘Lang. of Traffic Policemen’ in AS XXXVII:4 271: oklahoma credit card, n. A can and siphon for stealing gasoline from an automobile tank.
[US]E. Shepard Doom Pussy 137: ‘Perhaps you could siphon gas out of the Associated Press jeep when we get there.’ [...] ‘Can’t do that without an Oklahoma credit card.’.
[US]Amer. Motorcyclist Oct. 12: As for the so-called ‘Oklahoma credit card’ system of gas siphoning, remember that it takes only a few drops of gasoline in the lungs to bring on pneumonia and possibly a speedy death.
[US]E. Abbey Monkey Wrench Gang 234: He groped under the seats until he found his Oklahoma credit card, a length of neoprene tubing.
[US]J.T. Honea Trouble Times Two 131: The real trick to using an Oklahoma Credit Card is knowing when to stop sucking on the hose.
Oklahoma guarantee (n.)

(US) no guarantee.

[US]Trans. of Amer. Wildlife Fndn 8 73: The man said, ’Well, all I can give you is an Oklahoma guarantee.’ [...] ‘What is an Oklahoma guarantee?’ ‘Well, if I borrow this money and don't pay you back I'm just a dirty sob’.
[US]Larson & Wiggins-Porter History of Humble Oil 32: The unscrupulous use of the confusion in Indian titles that gave rise in Texas to the scornful term, ‘an Oklahoma guarantee’.
[US]Western Folklore XXV:3 39: Oklahoma guarantee. ‘Means they will take it all away from you if they can.’ No guarantee at all. Houston, Texas, 1948-51.
[US]J. Christgau Kokomo Joe 21: ‘I’ll give my “Oklahoma Guarantee” on it.’ ‘An “Oklahoma Guarantee”? What's that?’ ‘I can't say for sure,’ he answered through his broad smile. ‘Because my horses always win, and I have never had to make good on the guarantee’.
Oklahoma rain (n.)

(US) a dust storm.

[US]DN V 37: Oklahoma rain, n.phr. A sand storm, common in that state .
[US]R.F. Adams Cowboy Lingo 203: A sandstorm was an ‘Oklahoma rain’.
V. Randolph We Always Lie to Strangers 185: Along the Western edge of Arkansas, when a wind blows sand and dirt into the houses the old folks don’t call it a dust storm. They call it an Oklahoma rain.
[US]Indep. Record (Helena, MO) 9 Oct. 3/7: Talk about the weather might include some talk about Oklahoma rain (meaning a sandstorm).