1. [v]  gradually deprive (infants) of mother's milk; "she weaned her baby when he was 3 months old and started him on powdered milk"
2. [v]  detach the affections of

1. \Wean\, v. t. [imp. & p. p. {Weaned}; p. pr. & vb. n.
   {Weaning}.] [OE. wenen, AS. wenian, wennan, to accustom; akin
   to D. wennen, G. gew["o]hnen, OHG. giwennan, Icel. venja, Sw.
   v["a]nja, Dan. v[ae]nne, Icel. vanr accustomed, wont; cf. AS.
   [=a]wenian to wean, G. entw["o]hnen. See {Wont}, a.]
   1. To accustom and reconcile, as a child or other young
      animal, to a want or deprivation of mother's milk; to take
      from the breast or udder; to cause to cease to depend on
      the mother nourishment.
            And the child grew, and was weaned; and Abraham made
            a great feast the same day that Isaac was weaned.
                                                  --Gen. xxi. 8.
   2. Hence, to detach or alienate the affections of, from any
      object of desire; to reconcile to the want or loss of
      anything. ``Wean them from themselves.'' --Shak.
            The troubles of age were intended . . . to wean us
            gradually from our fondness of life.  --Swift.
   

2. \Wean\, n.
   A weanling; a young child.
         I, being but a yearling wean.            --Mrs.
                                                  Browning.
   

Among the Hebrews children (whom it was customary for the mothers to nurse, Ex. 2:7-9; 1 Sam. 1:23; Cant. 8:1) were not generally weaned till they were three or four years old.