Nutcracker esophagus, jackhammer esophagus, or hypercontractile peristalsis, is a disorder of the movement of the esophagus characterized by contractions in the smooth muscle of the esophagus in a normal sequence but at an excessive amplitude or duration.

The nutcracker syndrome results most commonly from the compression of the left renal vein between the abdominal aorta and superior mesenteric artery, although other variants exist.

Nucifraga columbiana, a passerine bird in the family Corvidae, ashy-grey all over except for the black-and-white wings and central tail feathers.

Tool for cracking hard shells.

Bird known for hoarding seeds.