cellar; crypt

sinus (anatomy); subterranean passage

The Injustice to Dou E (popular drama by 關漢卿|关汉卿[Guan1 Han4 qing1])

(anatomy) sinoatrial node; sinuatrial node

(medicine) sinus rhythm

(lit.) love aperture; (fig.) interest in love matters

dog hole; gap caused by missing teeth; fig. den of thieves

Matthew; St Matthew the evangelist; less common variant of 馬太|马太[Ma3 tai4] (preferred by the Catholic Church)

(literary) doubts; suspicions; cause for suspicion

sphenoidal sinus