Main Entry: cha·la·sia Pronunciation: k&-'lA-zh&, ka- Function: noun : the relaxation of a ring of muscle (as the cardiac sphincter ofthe esophagus) surrounding a bodily opening
chalasia cha·la·sia (kə-lā'zē-ə, -zhə) or cha·la·sis (-lā'sĭs) n. The inhibition and relaxation of a previously sustained contraction of a muscle or synergistic group of muscles, such as the cardiac sphincter.
