hard nut to crack

a hard nut (to crack)

A person, thing, situation, or problem that is particularly difficult to understand, solve, or deal with. I've been dating Jenny for over a year, and I still think she's a hard nut to crack! Figuring out the best way to modernize our product without alienating existing customers is definitely a hard nut to crack. The spy we captured is a hard nut; he hasn't said a thing since we began the interrogation.
See also: hard, nut
Farlex Dictionary of Idioms. © 2022 Farlex, Inc, all rights reserved.

(a) hard nut to crack

 and (a) tough nut to crack
Fig. difficult person or problem to deal with. This problem is getting me down. It's a hard nut to crack. Tom sure is a hard nut to crack. I can't figure him out.
See also: crack, hard, nut, to
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.

hard nut to crack

Also, tough nut to crack. A difficult problem; also, an individual who is difficult to deal with. For example, This assignment is a hard nut to crack, or It won't be easy getting her approval; she's a tough nut to crack. This metaphoric expression alludes to hard-shelled nuts like walnuts. [Early 1700s]
See also: crack, hard, nut, to
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

tough nut to crack, a

A difficult problem; a hard person to deal with. This early analogy, also put as a hard nut to crack, was first drawn in the early eighteenth century. Benjamin Franklin used it in a letter in 1745: “Fortified towns are hard nuts to crack; and your teeth have not been accustomed to it.” A similar term from a somewhat later era is tough customer, likewise meaning a person difficult to deal with. Dickens used it in Barnaby Rudge (1841): “Rather a tough customer in argument, Joe, if anybody was to try and tackle him.”
See also: nut, to, tough
The Dictionary of Clichés by Christine Ammer Copyright © 2013 by Christine Ammer
See also:
References in classic literature ?
If it's for me, I'm a hard nut to crack, and I take it standing up.
"Oh, he's a hard nut to crack," said one of the officers who was sitting in the shadow at the other side of the fire.
He said: "Unsurprisingly, Cosla is a hard nut to crack.
Fighters' Lapologang Motlogi kept United defence on its toes but failed to gets the better of them as they proved to be a hard nut to crack.
The bankers were expected to protest the change but have instead embraced it, alleging that it is easier to beat Gor at Machakos unlike at Kisumu, where they have proved a hard nut to crack. KCB assistant coach Sammy 'Pamzo' Omollo, Gor are beatable at Machakos as they will not enjoy massive support from fans and there is no clear home advantage.
The visitors proved a hard nut to crack and the first half was goalless but Killearn went ahead early in the second half and then seemed to be safe when Rob Roy went down to 10 men.
They are a hard nut to crack and have top-class players.
"Nairobi Simba have always been a hard nut to crack and I am sure they will come hard on us, noting that a loss can have them relegated.
Such kind of candidates leaves the pathetic impact on the mind of educated people that CSS is hard nut to crack. 90 per cent candidates fail in English essay because of inability to express their ideas and opinion in an effective manner in that language.
Misconceptions are a notoriously hard nut to crack even for an emerging power like China.
I genuinely believe that this is a knee-jerk reaction to the epidemic of violent crime but I do admit that this is a hard nut to crack.
Darren Mullen's men have been a hard nut to crack in their first season in the top flight, particularly at home where they taken seven points and lost just one of four league outings.
Talking to The Nation, Mr Faisal Khan, a banker and father of a female candidate, said that to get admission to public medical and dental colleges had become a hard nut to crack for poor students.
An Iranian administration adept at handling economic sanctions in the light of American sanctions could be a hard nut to crack for Washington.
'This is the truth of the matter; the forces see Ortom as a hard nut to crack, given his stance on the anti-open grazing law as their reason.'