hard nut to crack

Noun

hard nut to crack (plural hard nuts to crack)

1. (idiomatic) A problem that is challenging to solve.
   • He saw the dilemma. . . . It was a hard nut to crack. He could see no way out of it.1893, Grant Allen, chapter 11, in Michael's Crag
   • Germany's inflation proves a hard nut to crack.1991 June 14, Leonard Silk, “Economic Scene; Predicting When Upturn Will Start”, in New York Times, retrieved 22 Sep 2011
2. (broadly, idiomatic) A situation, person, group, etc. which is difficult to overcome or deal with.
   • The coast lad found the veteran Mike McTigue a hard nut to crack and judging from the look on the Californian's face when the final bell sounded, he was mighty happy that the fight was over.1928 June 8, “Mike McTigue Gives Emanuel a Real Fight”, in Milwaukee Journal, retrieved 22 Sep 2011, page 2
   • "But Belarus is a hard nut to crack, and it has used these methods to slip out of these East-West pincers before," says Alexander Klaskovsky.2011 January 12, Simon Shuster, “Will the E.U. Let Belarus' Despot Off the Hook?”, in Time
3. (idiomatic) A place, opportunity, etc. to which it is difficult to gain entry.
   • The next day Archie, with Andrew Macpherson and Cluny Campbell, made their way through the woods until within sight of the castle. . . .
     "It would be a hard nut to crack, Sir Archie," his lieutenant said. "Unless by famine, the place could scarce be taken."1885, G. A. Henty, chapter 7, in In Freedom's Cause
   • Durango, however, may be a hard nut to crack, as it is strong strategically and is reported guarded by 4000 rebels.1929 March 15, “Five Mexican Armies March to Meet Rebels”, in Reading Eagle, USA, retrieved 22 Sep 2011, page 1
4. (idiomatic) An amount that is difficult to finance.
5. Used other than figuratively or idiomatically: see hard, nut, crack.

   Synonyms:

   difficult nut to crack, tough nut to crack