4×4
noun [ C or U ] uk/ˌfɔː.baɪˈfɔːr/ us/ˌfɔːr.baɪˈfɔːr/
四轮驱动（four-wheel drive的简称，即前后四个车轮均有动力的汽车，即使在恶劣路面上也可行驶自如）
abbreviation for four-wheel drive : a vehicle that has power supplied by the engine to all four wheels so that it can travel easily over difficult ground