n a groove or furrow (especially one in soft earth caused by wheels)
n a settled and monotonous routine that is hard to escape
n applies to nonhuman mammals: a state or period of heightened sexual arousal and activity
v be in a state of sexual excitement; of male mammals
v hollow out in the form of a furrow or groove
n. 车辙( rut的名词复数 ); 犁沟; 常规; 老规矩