东汉末,刘备三次往隆中(山名,在今湖北襄阳)聘请隐居于草庐的诸葛亮出来帮助打天下。后用来指诚心诚意再三邀请或访问repeatedly request somebody to take up a responsible post;call on a famous scholar repeadedly to solicit his help;make three calls at a thatshed cottage and request the owner to take up a responsible post