noun, proper name · a person who is a specialist worker or trained professional in a particular field

社会各界人士都积极参与了这项公益活动。

proper name, noun · a member of the senior ministerial class or an educated person in ancient China

士大夫在古代中国拥有很高的社会地位。

noun · a soldier or a noncommissioned officer in the military

他在部队服役多年，现在是一名中士。

proper name, noun · surname Shi

那位新来的体育老师姓士，这个姓氏比较少见。