from
The Collaborative International Dictionary of English v.0.48
Diaphragm \Di"a*phragm\, n. [L. diaphragma, Gr. ?, fr. ? to
fence by a partition wall; dia` through + ?, ?, to fence,
inclose; prob. akin to L. fareire to stuff: cf. F.
diaphragme. See {Farce}.]
1. A dividing membrane or thin partition, commonly with an
opening through it.
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2. (Anat.) The muscular and tendinous partition separating
the cavity of the chest from that of the abdomen; the
midriff.
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3. (Zool.) A calcareous plate which divides the cavity of
certain shells into two parts.
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4. (Opt.) 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.
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5. (Mach.) A partition in any compartment, for various
purposes.
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{Diaphragm pump}, one in which a flexible diaphragm takes the
place of a piston.
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