Pessary

[Little_Girl]

An instrument or device to be introduced into and worn in
the vagina, to support the uterus, or remedy a malposition.

[Dave Paprocki]

(n. obs.) A medicated vaginal suppository or a contraceptive diaphragm.

[Rihanna]

A small soluble block that is inserted into the vagina to treat infection or as a contraceptive.