Dĭ'a-phrāgm, n.
(-frăm), n. [Gr. διάφραγμα, from δια-φραγνύναι, to fence by a partition wall, from διά, through, and φραγνύναι, φράσσειν, to fence, inclose, Lat. diaphragma, Fr. diaphragme.]
Sense 1. A dividing membrane or thin partition, commonly with an opening through it.
Sense 2. (Anat.) The muscle separating the chest or thorax from the abdomen or lower belly; the midriff.
Sense 3. (Conch.) A straight calcareous plate which divides the cavity of certain shells into two parts only. Brande.
Sense 4. (Opt.) A plate with a circular opening, used, in instruments, to cut off marginal portions of a beam of light, as at the focus of a telescope.
Sense 5. (Mech.) A partition in any compartment, for various purposes.