1. 膈;膈膜
Your diaphragm is a muscle between your lungs and your stomach. It is used when you breathe.

2. (女性避孕用)子宫帽
A diaphragm is a circular rubber contraceptive device that a woman places inside her vagina.

1. a mechanical device in a camera that controls size of aperture of the lens

e.g. the new cameras adjust the diaphragm automatically

Synonym: stop

2. electro-acoustic transducer that vibrates to receive or produce sound waves

3. a contraceptive device consisting of a flexible dome-shaped cup made of rubber or plastic
it is filled with spermicide and fitted over the uterine cervix

Synonym: pessarycontraceptive diaphragm

4. (anatomy) a muscular partition separating the abdominal and thoracic cavities
functions in respiration

Synonym: midriff