tough nut to crack

a tough nut

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 tough nut to crack! Figuring out the best way to modernize our product without alienating existing customers is definitely a tough nut to crack. The spy we captured is a tough nut; he hasn't said a thing since we began the interrogation.
See also: nut, tough

tough nut to crack

verb
See also: crack, nut, tough

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
References in classic literature ?
He tries this on very much with me, but I flatter myself he has got a tough nut to crack. I know that from my glass.
The young and short course proved a tough nut to crack for the 80-player field as only 15 players cracked par with several big names struggling.
Howe will be glad to get back to Dean Court, where they have beaten West Ham and Chelsea comfortably in their last two home games, but Wolves could prove to be a tough nut to crack.
Neilson, 38, who replaced Csaba Laszlo last week, insists the third-top Highlanders will be a tough nut to crack.
Though Creamline drew a huge confidence boost with its Game Two win, Valdez knows that Pocari Sweat-Air Force, backed by its championship experience, will be a tough nut to crack.
But achieving the Rs 13 billion target would be tough nut to crack, he said.
It's got an Assassin's Creed feel and the huge boss men battles are superb the best thing about the game but, be warned, it's a tough nut to crack.
Tereapii Tapoki, a police officer from Rarotonga, the largest of the 15 palm-fringed Pacific islands that make up the country, hit on the solution after finding throwing sports a tough nut to crack with no equipment available.
Rebecca Menzies-trained Halycon Days proved a tough nut to crack and saw off Supreme Asset by a neck in the two-mile handicap chase.
ALAN PARDEW is looking forward to pitting his wits against Sam Allardyce tomorrow - but has warned that his old adversaries Sunderland will be a tough nut to crack.
However, he has far less on his plate, and with conditions to suit, he should be a tough nut to crack.
The Sunset Strip in West Hollywood, a mecca for tourists, has nevertheless proven a tough nut to crack for restaurateurs.
Favourite Prince Gibraltar, an unlucky-in-running third in the French Derby, looked to have all bases covered but found first Teletext a tough nut to crack before Gallante hit another gear in the Derrick Smith colours to foil Jean-Claude Rouget's hotpot.
India, June 10 -- Apple has signed a deal with Sony Music Entertainment, the major label that had remained a tough nut to crack all these months, for the much anticipated iRadio service.