1.COUNTRYSIDE especially AusE a country area where few people live 〔人口稀疏的〕偏远乡间
2.American EnglishAmECOUNTRYSIDE an area, especially in the mountains, away from roads and towns 〔远离大路和城镇的〕偏远山区
Examples from the Corpus
back country• Thirteen remain in the Santa Barbara Countyback country.• When Taylor asked some of the boys at Midvale to join him in the back country, all but William Fannon refused.