RN  
noun uk/ˌɑːrˈen/ us/ˌɑːrˈen/
  (NURSE)      
  [ C ] US注册护士(可用于姓名后) 
a  registered nurse ; also used after the name of a registered nurse
  An RN makes about $30 an hour in this city. 在这座城市里一名注册护士的时薪约为30美元。 
 Alice Brody, RN 注册护士爱丽丝·布罗第 
   (NAVY)      
 UK英国皇家海军(尤用于海军军官姓名后,Royal Navy的缩写) 
abbreviation for Royal Navy: used especially after the names of officers in the British navy
  Captain H. Doughty, RN 英国皇家海军上校 H.道蒂