The diaphragm is a large, thin muscle under your lungs that helps you breathe by moving up and down. The word can also refer to thin separating layers in devices, such as camera lenses or speakers.
From Greek "diaphragma" meaning "partition" or "wall," from "diaphrassein" (to fence off), formed from "dia-" (through) and "phrassein" (to enclose). It entered English through Latin scientific vocabulary.
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