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1. A groove or furrow (especially one in soft earth caused by wheels)
    
2. A settled and monotonous routine that is hard to escape
   "they fell into a conversational rut";
   - groove
    
3. Applies to nonhuman mammals: a state or period of heightened sexual arousal and activity
   - estrus [N. Amer], oestrus [Brit], heat

1. Be in a state of sexual excitement; of male mammals
    
2. Hollow out in the form of a furrow or groove
   "rut soil";
   - furrow, groove

Derived forms: rutting, rutted, ruts

Type of: be, channel, cut into, delve [archaic], dig, groove, MO, modus operandi, physical condition, physiological condition, physiological state, routine, turn over

Antonym: anoestrus

Encyclopedia: Rut, Tolmin