Yes, rut is a Scrabble word!
...and is worth 3 points in Scrabble, and 4 points in Words with Friends
rut
Verb
1. Be in a state of sexual excitement; of male mammals
2. Hollow out in the form of a furrow or groove
Noun
1. A groove or furrow (especially one in soft earth caused by wheels)
2. A settled and monotonous routine that is hard to escape
3. Applies to nonhuman mammals: a state or period of heightened sexual arousal and activity
What Scrabble words can I make with the letters in rut?
2 Letter Words