What is Diaphragm ?

Diaphragm is (noun) 1. a thin sheet which vibrates with noise the diaphragm in a hearing aid 2. a thin layer of tissue which separates the chest from the abdomen, and pulls air into the lungs when you breathe The stomach lies in the left upper part of the abdomen, just under the diaphragm. 3. a contraceptive device for women


source: Easier English, Student Dictionary Upper Intermediate Level