achalasia

noun Medicine/Medical.

1. inability of a circular muscle, especially of the esophagus or rectum, to relax, resulting in widening of the structure above the muscular constriction.

noun

1. pathol failure of the cardiac sphincter of the oesophagus to relax, resulting in difficulty in swallowing

n.

1. The failure of a ring of muscle fibers, such as a sphincter, to relax.