Green’s Dictionary of Slang

crack v.4

1. (orig. Aus.) to act in a given manner, defined by some form of comb., e.g. crack hardy

[Aus]G.W. Turner Eng. Lang. in Aus. and N.Z. 108: An Adelaide student reported [...] in 1968 that in April of that year her brother on a trip to Sydney found that the fashionable slang word was then crack. You would crack a greenie ‘go surfing’, crack a coldie ‘open a bottle of beer’.
[Aus]Lette & Carey Puberty Blues 51: ‘What happened?’ ‘He cracked a mental.’.

2. (Aus.) to pretend, to sham; thus crack a deaf ’un, to pretend to be deaf, or not to hear.

[Aus]Sydney Sportsman (Surry Hills, NSW) 10 Oct. 1/1: For years past I’ve been trying to unearth a self-admitted cronk ’un, but they will all persist in cracking dead squares.
[Aus]Bulletin (Sydney) 15 Nov. 31/2: But I tell yer times is getting so hard that I has ter crack deaf and write it on paper when I arsks for chuck; an’ sometimes I forgets myself. That’s ’ow I ’eard what you said.
[Aus]E. Dyson ‘The Big Spoof’ in Benno and Some of the Push 215: Little Benno, lyin’ low, crackin’ soft silly, does the ’gun fer all he owns, gets home with the boodle.
[Aus]D. Whish-Wilson Old Scores [ebook] Riley talked like a mug, but that was just him cracking dumb.

3. (US black) to happen.

[US]‘Touré’ Portable Promised Land (ms.) 160: We Words (My Favorite Things) [...] It’s crackin. What’s poppin? What’s hapnin? What’s cracka-lackin? Whatever’s clever.

In phrases

crack hardy (v.) (Aus.)

1. to put up with discomfort, to ‘grin and bear it’; thus as adj. crack-hardy, resilient.

[Aus]Sun. Times (Perth) 30 Jan. 2nd sect. 4/7: Those to whom the Slang Dictionary is a sealed tome needn’t read this. A very damp visitor [...] deployed into the bar of the Shamrock from the office, aad held forth on the hotel clerk. ‘The (hic) cow wouldn’t change me cheque. Me (hic) ’oo’s got thousands in the bank [...] The clerk, whose name is Hârdy, is a very quiet, small gent, but a bull-ant when roused. ‘What orter I .do to ’im for not cashin’ me cheque?’ he gurgled. [...] A pressman present ventured an answer — ‘Crack Hardy,’ he suggested.
[Aus]Bulletin (Sydney) 11 Dec. 15/4: I don’t mind telling you that it took me all my time to crack hardy.
[Aus]J. Doone Timely Tips For New Australians 22: TO ‘CRACK HARDY.’ — To simulate courage.
[Aus]K.S. Prichard Working Bullocks 184: All that there was of him was grit really. He was so crack-hardy and chirpy always.
[US]Dly News (NY) 30 May 10/3: Where we say ‘Grin and bear it,’ the Australian says ‘Crack Hardy’.
[Aus](con. 1936–46) K.S. Prichard Winged Seeds (1984) 185: I feel it [...] You know that. But I’ve got to crack hardy.
[Aus]B. Humphries Barry McKenzie [comic strip] in Complete Barry McKenzie (1988) 102: You don’t have to act brave or crack hardy with old Bazza McKenzie.
[Aus](con. 1941) R. Beilby Gunner 118: Of course he’s cracking hardy now but we’re going to have trouble with him very soon.
[Aus]R. Beckett Dinkum Aussie Dict. 16: Crack hardy: To act in a courageous manner or to put up with conditions of extreme hardship.
[Aus]G. Seal Lingo 2: To decode phrases like flat to the boards like a lizard drinking, looks as though they might cut up rusty (or rough) or it’s cracking hardy today..., the listener needs to be a member of the group that habitually utters such oddities.
at 🌐 There was nothing for it but to grit our teeth and crack hardy, so we plunged into the gloom.
[Aus]C. Hammer Opal Country 91: ‘How was Garry today?’ [...] ‘Excellent. It was very confronting, but he’s cracking hardy’.

2. to keep a secret.

[UK]Partridge DSUE (8th edn) 263/2: C.20.