pessary
noun /ˈpesəri/
  /ˈpesəri/
(plural pessaries)
- a small piece of solid medicine that is placed inside a woman’s vagina and left to dissolve, used to cure an infection or to prevent her from becoming pregnant(治疗炎症或避孕用的)阴道栓剂 
- a device that is placed inside a woman’s vagina to support the womb子宫托 
词源late Middle English: from late Latin pessarium, based on Greek pessos ‘oval stone’ (used in board games).