Medical term for a natural opening or fissure in the body, especially the esophageal hiatus of the diaphragm. Also used for lyriform fissures in arachnids. Not a general word for 'hole'.
A hiatal hernia is a condition where part of the stomach protrudes into the chest cavity through the esophageal hiatus of the diaphragm.
The exoskeleton of spiders has sensory organs called lyrifissures.
hiatal hernia; hiatus hernia
Compound of 裂 (れつ, 'split, tear') and 孔 (こう, 'hole, opening'), literally 'split hole'. The reading れっこう results from the assimilation of れつ + こう.