nut
Pronunciation: /nʌt/
noun
- 1a fruit consisting of a hard or tough shell around an edible kernel: he was cracking nuts with his teeth
- the hard kernel of a nut: savoury snacks like crisps and nuts
- (usually nuts) a small lump of something hard or solid, especially coal.
- 2a small flat piece of metal or other material, typically square or hexagonal, with a threaded hole through it for screwing on to a bolt as a fastener: fix the new pipe and tighten the nuts the final wheel nut was tightened
- the part at the lower end of the bow of a violin or similar instrument, with a screw for adjusting the tension of the hair.
verb ( nuts, nutting, nutted)

Phrases
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do one's nut
- British informal become extremely angry or agitated: I hope my mum hasn’t heard about this, or she’ll be doing her nut
-
nuts and bolts
- informal the basic practical details: the nuts and bolts of making a movie
-
off one's nut
- informal out of one’s mind; crazy.
-
a tough (or hard) nut
- informal someone who is difficult to deal with; a formidable person.
-
a tough (or hard) nut to crack
- informal a difficult problem or an opponent that is hard to beat.
-
use (or take) a sledgehammer to crack a nut
- informal use disproportionately drastic measures to deal with a simple problem.

Origin:
Old English hnutu, of Germanic origin; related to Dutch noot and German Nuss