From WordNet (r) 3.0 (2006):
rut
n 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" [syn: rut, groove]
3: applies to nonhuman mammals: a state or period of heightened
sexual arousal and activity [syn: estrus, oestrus,
heat, rut] [ant: anestrum, anestrus, anoestrum,
anoestrus]
v 1: be in a state of sexual excitement; of male mammals
2: hollow out in the form of a furrow or groove; "furrow soil"
[syn: furrow, rut, groove]