Translate sinus | into French | into German | into Italian | into Spanish Definition of sinus
noun
1 (often
sinuses)
Anatomy &
Zoology a cavity within a bone or other tissue, especially one in the bones of the face or skull connecting with the nasal cavities. an irregular venous or lymphatic cavity, reservoir, or dilated vessel. Medicine an infected tract leading from a deep-seated infection and discharging pus to the surface. Botany a rounded notch between two lobes on the margin of a leaf or petal.
2 [as modifier] Physiology relating to or denoting the sinoatrial node of the heart or its function as a pacemaker:sinus rhythm sinus tachycardia