WordReference Random House Unabridged Dictionary of American English © 2025
ach•a•la•sia
(ak′ə lā′zhə, -zhē ə, -zē ə),USA pronunciation n. [Med.]
- Medicine, Pathologyinability of a circular muscle, esp. of the esophagus or rectum, to relax, resulting in widening of the structure above the muscular constriction.
- a-6 + Greek chálas(is) (chala- (stem of chalân to loosen) + -sis -sis) + -ia 1910–15