[ 'dʌɪəfram ]
1》 a dome-shaped muscular partition separating the thorax from the abdomen in mammals.
2》 a thin sheet of material forming a partition.
↘a taut flexible membrane in mechanical or acoustic systems.
3》 a thin contraceptive cap fitting over the cervix.
4》 a device for varying the effective aperture of the lens in a camera or other optical system.
ME: from late L. ~a , from Gk, from dia 'through, apart' + phragma 'a fence'.