Green’s Dictionary of Slang

hard word n.

1. (Anglo-Irish) a tip-off, a warning; thus give someone the hard word, to warn.

[Ire]S. Lover Handy Andy 369: He suspects you gave me the hard word.
[Ire]Joyce ‘Two Gallants’ Dubliners (1956) 49: Whenever any job was vacant his friend was always ready to give him the hard word.
[Ire](con. 1860s) G.A. Little Malachi Horan Remembers 73: I would never be passing his house after but he and his wife would be running out to the fence to give me the hard word.
[Aus]N. Cummins Tales of the Honey Badger [ebook] [A]nd recently having been given the hard word, I decided to attempt an unorthodox second-storey Mission Impossible entry.

2. (Aus.) an outrageous request.

[Aus](con. WWI) A.G. Pretty Gloss. of Sl. [...] in the A.I.F. 1921–1924 (rev. t/s) n.p.: hard word. An outrageous demand. A request for a favor vigorously expressed.
[Aus]J. Byrell (con. 1959) Up the Cross 16: ‘D’ya expect us to hang it on to Whiffy to hit you you with the hard word about taking you out’.

In phrases

put the hard word on (v.) (orig. Aus./N.Z.)

1. to make demands (esp. financial or sexual) of someone.

[Aus]Aussie (France) 6 Aug. 11/2: ‘I’m off now to put the hard word on the Babbling Brook for some more dripping!’ [...] Our prize Section Dope was trying to put the hard word on the Quarter Bloke for a tin of butter.
[UK](con. WWI) E. Lynch Somme Mud 49: Darky [...] ends by putting the hard word on them for ‘a bit of buckshee tucker.’.
[Aus]K. Tennant Battlers 141: There’s Jasprey now [...] Come on. Let’s put the hard word on him.
[Aus]D. Stivens Jimmy Brockett 117: If I’d slung a diamond bracelet her way before I’d put the hard word on her, it’d have been a very different story.
[Aus]A. Buzo Rooted II i: Look, if he’s putting the hard word on you, if he’s being in any way coercive [...] I’ll take care of it.
[Aus]B. Humphries Traveller’s Tool 7: Publishers have been putting the hard word on me for yonks to spill the beans, tell it like it is and tip the bucket.
[Aus]M.B. ‘Chopper’ Read How to Shoot Friends 52: The White Dove proceeded to put the hard word on him for a truck load of firewood.
[Aus]M.B. ‘Chopper’ Read Chopper 4 77: I was a bit pissed and I put the hard word on her [...] ‘Lend me $200.’.
[Aus]G. Disher Kill Shot [ebook] [He] put the hard word on his pizza cooks, counter staff and delivery boys to front up.

2. to interrogate, to question.

[Aus]‘Banjo’ Paterson Shearer’s Colt 17: I’d put the word on this red bloke if I was you, trooper.

3. to reprimand, to scold.

[Aus]P. Temple Broken Shore (2007) [ebook] Put the hard word on Debbie. She won’t listen to her mum.
[Aus]P. Temple Truth 116: He knew he should have woken her, talked to her, showed concern, put the hard word on her.