DIAPHRAGM

noun Etymology: Middle English diafragma, from Late Latin ~a, from Greek, from diaphrassein to barricade, from dia- + phrassein to enclose Date: 14th century a body partition of muscle and connective tissue, a dividing membrane or thin partition especially in a tube, 3. a more or less rigid partition in the body or shell of an invertebrate, a transverse septum in a plant stem, a device that limits the aperture of a lens or optical system, a thin flexible disk (as in a microphone or loudspeaker) that vibrates when struck by sound waves or that vibrates to generate sound waves, a molded cap usually of thin rubber fitted over the uterine cervix to act as a mechanical contraceptive barrier, ~atic adjective ~atically adverb