[ ə'tri:ʃə , -zɪə ]
■ noun
1》 Medicine absence or abnormal narrowing of an opening or passage in the body.
2》 Physiology the degeneration of those Graafian follicles which do not ovulate during the menstrual cycle.
Origin
C19: from a- 1 + Gk trēsis 'perforation' + -ia 1 .