a person who works in an institution but does not live there, especially a doctor or other worker in a hospital 不住机构内的工作人员;(尤指)非住院医生,非住院的医院员工 Word Originmid 16th cent. (as an adjective in the sense ‘external’): from French externe or Latin externus, from exter ‘outer’. The word was used by Shakespeare to mean ‘outward appearance’; current noun senses date from the early 17th cent.