The Oxford Thesaurus An A-Z Dictionary of Synonyms - rut n.

1) groove, furrow, wheel-mark, track, trough: In the winter the ruts in the lane fill with water and freeze, making driving difficult. 2) pattern, habit, routine, groove, grind, treadmill, dead end, Colloq rat race: After 27 years as a horse groom, I'm beginning to feel I'm stuck in a rut.