Diaphragm

[Sarah]

A thin flexible disk, usually made of rubber, that is stuck up in a woman's pussy so that it covers the cervix and keeps the boyfriend's sperm from gettin' to her eggs when he cums inside her, thereby keeping her from gettin' knocked up.

[Julian]

A [circular] device usually made of [rubber] placed in a womens vagina to cover the [clevis]. It is used during sexual intercourse to protect her from getting the males sperm inside of her

[Merna]

A dome-shaped muscular partition separating the thorax from the abdomen in mammals. It plays a major role in breathing, as its contraction increases the volume of the thorax and so inflates the lungs.

[Jessica]

The part of the human body that tightens and moves down to create lower air pressure in the lungs than in the outside environment, allowing air to move into the lungs. This part then relaxes and moves back up, generating higher air pressure in the lungs than the outside environment, forcing [carbon dioxide] out of the lungs. This part also separates the chest cavity (cardiovasuclar and respiratory) from the abdominal cavity ([digestive system]), which is why your chest expands as you breathe. Also that fancy part of an [air horn] that rapidly vibrates in response to air movement, generating that screeching sound.