toughest nut to crack
Most difficult problem
The toughest nut to crack is the most difficult problem to solve or person to persuade.
Like a nut with an especially hard shell, some challenges resist all ordinary efforts: Getting him to change his mind was the toughest nut to crack.
The phrase emphasizes that while other difficulties may yield, this one remains stubbornly resistant.
- Gordian knotSeemingly unsolvable difficulty
- problemMatter requiring resolution
- dilemmaForced choice between undesirables
- puzzleChallenge testing ingenuity
- brain teaserProblem requiring clever thought
challenge · tall order · obstacle · brick wall · formidable · impasse · sticking point · enigma · conundrum · insurmountable · uphill battle · difficulty · hurdle · no easy feat · mystery · intricate · riddle · hard case
toughest nut to cracklow-hanging fruit
Readily attainable objectives
piece of cake · walk in the park · child's play · easy pickings · cakewalk
toughest nut to crackopen book
One easily understood
pushover · easy mark · soft touch · easy target · transparent
tough, tougher, toughest, toughly, toughness, toughen, toughened, toughening, nuttier