in one's nineties 意味

• （年齢が）90代で［に］
  

• in one's early nineties:    （年齢が）90代（の）前半［初め］で［に］
• in one's late nineties:    （年齢が）90代後半で［に］
• in one's mid-nineties:    （年齢が）90代半ばで［に］