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Medical Dictionary

sinus

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noun si·nus \ˈsī-nəs\

Medical Definition of sinus

  1. :  a cavity or hollow in the body: asa:  a narrow elongated tract extending from a focus of suppuration and serving for the discharge of pus <a tuberculous sinus>b (1):  a cavity in the substance of a bone of the skull that usually communicates with the nostrils and contains air (2):  a channel for venous blood (3):  a dilatation in a bodily canal or vessel




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a division or portion of a pool or whole

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