a tough nut to crack

Related to a tough nut to crack: for good measure, out of whack, slip through the cracks, perish the thought

a tough nut to crack

1. A difficult task to complete. Getting an A in this class will be a tough nut to crack. You want me to find more money in the budget? Ha, there's a tough nut to crack!
2. A challenging or unreasonable person to understand or deal with. Our super-strict principal is a tough nut to crack, so I hope Kate can convince her to let us host this event. Because our boss usually keeps to himself, I have no idea what his interests are—he's a tough nut to crack.
See also: crack, nut, tough
Farlex Dictionary of Idioms.

a tough nut to crack

or

a hard nut to crack

1. If you say that a problem is a tough nut to crack or a hard nut to crack, you mean that it is difficult to solve. The really tough nut to crack will be to persuade the older staff that change is necessary. The American market is a very hard nut to crack because it is so vast. Note: You can also just refer to a difficult problem as a tough nut or a hard nut. The tough nut for this government is undoubtedly the economy.
2. If you say that someone is a tough nut to crack or a hard nut to crack, you mean that they are difficult to defeat. Harrington has taken 17.5 points from a possible 20 in international singles, making him a tough nut to crack. Three wins and three draws prove United are a hard nut to crack.
See also: crack, nut, tough
Collins COBUILD Idioms Dictionary, 3rd ed.

tough nut to crack

verb
See tough egg to crack
See also: crack, nut, tough
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions

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, tough
The Dictionary of Clichés by Christine Ammer
See also:
  • tough nut to crack
  • tough nut to crack, a
  • be tough
  • be/get tough
  • hang tough
  • tough times
  • (as) tough as nails
  • tough as nails
  • follow
  • tough
References in periodicals archive
And, runner-up in two of his three starts in handicap hurdles, should prove a tough nut to crack if, as expected, the step-up to two and a half miles brings about further improvement.
TAKE GOOD LOUGH AT BISHOPS
However, they have been a tough nut to crack on their own patch and they should have enough to put Atvidaberg in their place tonight.
Ericsson has right message; footballmjallby v atvidaberg 6pm
Queens Park, buoyed by their victory over Afan Lido in the Welsh Cup, will prove a tough nut to crack.
Football: Bala look to close gap; CYMRU ALLIANCE premier NEWS
Blackburn Rovers will be a tough nut to crack, but it's vitally important to keep the interest going in the Cup for as long as possible as it can have a spin-off on the league.
Football: Beware our cup foes
WOLVERHAMPTON 8.30: RIGHTFUL RULER (74) is better than he showed on 'Poly' last week, he'll come on for that and Ronsard (65), Lady Hen (65) will probably find him a tough nut to crack. Culhane a has a tremendous record for Hills.
Racing: STOPWATCH
From what the top dogs at Rugby Police Station were saying this week, the problem is so big it's going to be a tough nut to crack.
SAMANTHA CLARKE: Time to get rid of 'Drugby' VIEW FROM THE CLOCK TOWER
England will be a tough nut to crack in Paris today, but victory will see France well on their way.
FRANCE ARE SIX PISTOLS; BETTING BOYS1
Catania are a tough nut to crack on their own patch, winning four of their six home games in the league this season, drawing 0-0 with high-flying Napoli and running champions Juventus close in a 1-0 defeat.
More gloom for Chievo; EUROPE
Port Talbot-based Lido, however, will be a tough nut to crack after being defeated finalists last year.
Football: Big day for Queens; WELSH CUP
Mighty Moss, the medium of several large wagers including one of an even pounds 15,000, found Last Option a tough nut to crack, but the latter was not helped by a mistake two out and though he rallied gamely, he was two and a half lengths adrift at the line.
HOME TRIUMPH FOR KING
Boca have won five of their last six home games but could find the Brazilians a tough nut to crack.
Fluminense could be tough
Having proved a tough nut to crack this season, the Ancients were swept aside 5-1 at Bangor City on Tuesday night following a disappointing display.
Football: Druids aim to bounce back
"Wexford will be a tough nut to crack - particularly as they are at home," said Hutton.
WEXFORD v HARPS; PREVIEWS
That form sets the standard in what looks a relatively weak affair and with further improvement expected on her second run for the yard she should prove a tough nut to crack. Conclusion She has an obvious chance but is priced accordingly at 13-8 and I'd rather be a layer than a backer.
BANKERS OR BLOWOUTS?
Now unbeaten in nine league games since Boxing Day, the Lilywhites had found Carmarthen a tough nut to crack as Kaid Mohamed's 71st-minute strike looked to have settled the affair.
Football: Pool rescue valuable point; WELSH PREMIER