The Collaborative International Dictionary of English v.0.48:

Rut \Rut\, n. [F. rut, OF. ruit, L. rugitus a roaring, fr.
   rugire to roar; -- so called from the noise made by deer in
   rutting time.]
   1. (Physiol.) Sexual desire or oestrus of deer, cattle, and
      various other mammals; heat; also, the period during which
      the oestrus exists.
      [1913 Webster]

   2. Roaring, as of waves breaking upon the shore; rote. See
      Rote.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Rut \Rut\, v. i. [imp. & p. p. Rutted; p. pr. & vb. n.
   Rutting.]
   To have a strong sexual impulse at the reproductive period;
   -- said of deer, cattle, etc.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Rut \Rut\, v. t.
   To cover in copulation. --Dryden.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Rut \Rut\, n. [variant of route.]
   A track worn by a wheel or by habitual passage of anything; a
   groove in which anything runs. Also used figuratively.
   [1913 Webster]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Rut \Rut\, v. t.
   To make a rut or ruts in; -- chiefly used as a past
   participle or a participial adj.; as, a rutted road.
   [1913 Webster]

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]