[ 'sʌɪnəs ]
■ noun
1》 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.
2》 Anatomy & Zoology an irregular venous or lymphatic cavity, reservoir, or dilated vessel.
3》 Medicine an infected tract leading from a deep-seated infection and discharging pus to the surface.
4》 Botany a rounded notch between two lobes on the margin of a leaf or petal.
5》 [as modifier ] Physiology relating to the sinoatrial node of the heart: ~ rhythm.
Derivatives
~itis noun
Origin
ME: from L., lit. 'recess, bend'.