a groove or furrow (especially one in soft earth caused by wheels)

a settled and monotonous routine that is hard to escape; they fell into a conversational rut

[ Syn: groove ]

applies to nonhuman mammals: a state or period of heightened sexual arousal and activity

[ Syn: estrus , oestrus , heat ]

be in a state of sexual excitement; of male mammals

hollow out in the form of a furrow or groove; furrow soil

[ Syn: furrow , groove ]