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sinus

11 ENTRIES FOUND:

si·nus

noun \ˈsī-nəs\

Definition of SINUS

: cavity, hollow: as a : a narrow elongated tract extending from a focus of suppuration and serving for the discharge of pus 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 c : a cleft or indentation between adjoining lobes (as of a leaf or corolla)

Origin of SINUS

Middle English, from Medieval Latin, from Latin, curve, fold, hollow
First Known Use: 15th century

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