noun
cervical os; os uteri; uterine orifice
Medical term for the opening of the cervix. Used in clinical and anatomical contexts.
出産時には子宮口が開きます。
The cervical os opens during childbirth.
医師が子宮口の状態を確認した。
The doctor checked the condition of the cervical os.
子宮頸部 is the 'uterine cervix' (the lower part of the uterus), whereas 子宮口 is the orifice itself.
Compound of 子宮 (shikyū, 'uterus') and 口 (kō, 'mouth, opening'). The reading こう for 口 is the on'yomi used in medical compounds.