Source : Webster's Revised Unabridged Dictionary (1913)

Rue \Rue\, v. t. [imp. & p. p. {Rued}; 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. reun, Icel.
   hruggr grieved, hrug[eth] sorrow. [root] 18. Cf. {Ruth}.]
   1. To lament; to regret extremely; to grieve for or over.
      --Chaucer.

            I wept to see, and rued it from my heart. --Chapmen.

            Thy will Chose freely what it now so justly rues.
                                                  --Milton.

   2. To cause to grieve; to afflict. [Obs.] ``God wot, it rueth
      me.'' --Chaucer.

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