Real Dictionary

diaphragm
countable noun: A diaphragm is a circular rubber contraceptive device that a woman places inside her vagina.
countable noun: Your diaphragm is a muscle between your lungs and your stomach. It is used when you breathe.

diaphragm in American English
the partition of muscles and tendons between the chest cavity and the abdominal cavity; midriff
noun: a muscular, membranous or ligamentous wall separating two cavities or limiting a cavity
transitive verb: to furnish with a diaphragm

diaphragm in Automotive Engineering
noun: A diaphragm is a flexible disk or membrane which moves under pressure and causes a rod in a brake or carburetor to move.

diaphragm in British English
noun: any separating membrane, esp the dome-shaped muscular partition that separates the abdominal and thoracic cavities in mammals

diaphragm in Chemical Engineering
noun: A diaphragm is a thin piece of impermeable material that moves and bends when there is a pressure difference across it.