Diaphragm
Pronunciation : Di"a*phragm
Part of Speech : n.
Etymology : [L. diaphragma, Gr. fareire to stuff: cf. F. diaphragme. See Farce.]
Definition : 1. A dividing membrane or thin partition, commonly with an opening through it.
2. (Anat.)
Defn: The muscular and tendinous partition separating the cavity of the chest from that of the abdomen; the midriff.
3. (Zo?l.)
Defn: A calcareous plate which divides the cavity of certain shells into two parts.
4. (Opt.)
Defn: A plate with an opening, which is generally circular, used in instruments to cut off marginal portions of a beam of light, as at the focus of a telescope.
5. (Mach.)
Defn: A partition in any compartment, for various purposes. Diaphragm pump, one in which a flexible diaphragm takes the place of a piston.
Source : Webster's Unabridged Dictionary, 1913