GNU Collaborative International Dictionary of English

Found one definition 

  1.       

    Diaphragm , n. [L. diaphragma, Gr. , fr.  to fence by a partition wall; διά 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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