rut - noun

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

a settled and monotonous routine that is hard to escape

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

rut - verb

• be in a state of sexual excitement; of male mammals
• hollow out in the form of a furrow or groove

rut - thesaurus

furrow   groove   heat   oestrus