The Collaborative International Dictionary of English v.0.48:

Rue \Rue\, v. t. [imp. & p. p. Rued (r[udd]d); p. pr. & vb. n.
   Ruing.] [OE. rewen, reouwen, to grive, make sorry, AS.
   hre['o]wan; akin to OS. hrewan, D. rouwen, OHG. hriuwan, G.
   reuen, Icel. hryggr grieved, hryg[eth] sorrow. [root] 18. Cf.
   Ruth.]
   1. To lament; to regret extremely; to grieve for or over.
      --Chaucer.
      [1913 Webster]

            I wept to see, and rued it from my heart. --Chapmen.
      [1913 Webster]

            Thy will
            Chose freely what it now so justly rues. --Milton.
      [1913 Webster]

   2. To cause to grieve; to afflict. [Obs.] "God wot, it rueth
      me." --Chaucer.
      [1913 Webster]

   3. To repent of, and withdraw from, as a bargain; to get
      released from. [Prov. Eng.]
      [1913 Webster]