Green’s Dictionary of Slang

crawfish v.

[SE crawfish, the US synon. for crayfish, a lobster-like crustacean. The term echoes the characteristic backward movement of the fish]
(Aus./N.Z./US)

1. (also crayfish) in fig. use, to back down, to renege on a previous statement, commitment (the image of is of personal humiliation).

[US]Ladies’ Repository (N.Y.) Oct. VIII:37 316/1: Craw-Fish, To back out; refuse to do any thing after starting to do it .
[US]Quincy (IL) Whig 12 Nov. 1/5: The council met the next day and ‘craw-fished’ — withdrawing the resolutions by an almost unanimous vote [DA].
[US]E. Eggleston Hoosier School-Master (1892) 147: You got me into this blamed mess, and now you want to crawfish.
[US]Schele De Vere Americanisms 263: The English term to rat, as applied to members who suddenly back out from a position they have long maintained, is in America replaced by the equally suggestive term to crawfish or crayfish, derived from the peculiar mode of locomotion of the animal.
[US]S.F. Examiner 22 Mar. n.p.: He crawfished out of the issue by claiming that he didn’t drink.
H. Lawson Short Stories 89: All the other chaps crawfished up and flung themselves round the corner and sidled into the bar after Dave.
[UK]Marvel XV:373 Jan. 6: We’ll think yer a skunk if yer crawfish at the ’levanth hour, Jake!
[Aus]Sun. Times (Perth) 24 Jan. 1/1: The yardman has also crawfished from confession.
[UK]Van Loan ‘The Indian Sign’ in Collier’s 1 Aug. in Van Loan (2004) 450: He crawfished, Milly [...] Crawled right into his hole and pulled it after him.
[Aus]Truth (Melbourne) 6 Mar. 5/1: In the parlance of political slang you have been pronounced ‘a cocktail, for crawfishifig to Fisher’.
[Aus]C.J. Dennis ‘Introduction’ in Rose of Spadgers [Internet] We don’t intend to be unkind or rude / Or crayfish on the things we said before.
[US]N. Algren Somebody in Boots 246: He knew Nubby wouldn’t let him crawfish out.
[US](con. 1944) N. Mailer Naked and Dead 73: He would have his choice of crawfishing or taking his punishment.
[US]R. Chandler Long Good-Bye 35: ‘In law no such obligation exists. Nobody has to tell the police anything, any time, anywhere.’ ‘Aw shut up,’ Green said impatiently. ‘You’re crawfishing and you know it.’.
[NZ]McGill Reed Dict. of N.Z. Sl. 54: crayfish 1. A contemptible person, as in one who crawls to authority blabbing about his mates. From the army in WWI. 2. A coward, often used in phrase to crayfish out, meaning you lost your nerve or backed away from something dangerous or risky. Late C19 ANZ.

2. in lit. use, to move backwards, to retreat, to run away.

[US]W.T. Thompson Major Jones’s Courtship (1872) 22: I crawfished out of that place monstrous quick, you may depend.
[US]Congressional Globe 1 Feb. 277/3: No sooner did they see the old British Lion rising up [...] than they crawfished back to 49°.
[US]W.F. Drannan Thirty-One Years on the Plains and in the Mountains (1903) 226: Riley said there was only one of two things to do, and that was to make the attack or crawfish.
[Aus]K.S. Prichard Haxby’s Circus 194: A bloke in one of the pubs [...] when he thought I was going to hit him, crayfished ... lay down on the floor, and said I couldn’t hit a man when he was down.
[US]‘Ed Lacy’ Men from the Boys (1967) 103: ‘I apologize, Mr. Berger,’ I said, crawfishing out of the room.