“城外”的英语可以翻译为：outside the city，out of town...

他乘车前往城外鲍勃的公寓。He rode uptown and made his way to Bob's apartment.我们的部队就在城外与敌人交火.Our troops joined with enemy forces just outside the city.我们从城外绕过去, 不要穿城而过.Let's go around the town, not through it....