1 (Anatomy) any separating membrane, esp. the dome-shaped muscular partition that separates the abdominal and thoracic cavities in mammals
Related adj →
2 a circular rubber or plastic contraceptive membrane placed over the mouth of the uterine cervix before copulation to prevent entrance of sperm
3 any thin dividing membrane
4 (Also called)
stop a disc with a fixed or adjustable aperture to control the amount of light or other radiation entering an optical instrument, such as a camera
5 a thin disc that vibrates when receiving or producing sound waves, used to convert sound signals to electrical signals or vice versa in telephones, etc.
a a porous plate or cylinder dividing an electrolytic cell, used to permit the passage of ions and prevent the mixing of products formed at the electrodes
b a semipermeable membrane used to separate two solutions in osmosis
7 (Botany) a transverse plate of cells that occurs in the stems of certain aquatic plants (C17: from Late Latin diaphragma, from Greek, from dia- + phragma fence)
n an adjustable diaphragm that regulates the amount of light entering an optical instrument, esp. a camera. It usually consists of a number of thin metal leaves arranged so that they open out into an approximately circular aperture, (Sometimes shortened to)
English Collins Dictionary - English Definition & Thesaurus
Add your entry in the Collaborative Dictionary.