sinus
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
Rhymes with SINUS
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