The Collaborative International Dictionary of English v.0.48:

Garble \Gar"ble\, v. t. [imp. & p. p. Garbled; p. pr. & vb. n.
   Garbling.] [Formerly, to pick out, sort, OF. grabeler, for
   garbeler to examine precisely, garble spices, fr. LL.
   garbellare to sift; cf. Sp. garbillar to sift, garbillo a
   coarse sieve, L. cribellum, dim. of cribrum sieve, akin to
   cernere to separate, sift (cf. E. Discern); or perh. rather
   from Ar. gharb[=a]l, gharbil, sieve.]
   1. To sift or bolt, to separate the fine or valuable parts of
      from the coarse and useless parts, or from dros or dirt;
      as, to garble spices. [Obs.]
      [1913 Webster]

   2. To pick out such parts of as may serve a purpose; to
      mutilate; to pervert; as, to garble a quotation; to garble
      an account.
      [1913 Webster]

WordNet (r) 3.0 (2006):

garbled
    adj 1: lacking orderly continuity; "a confused set of
           instructions"; "a confused dream about the end of the
           world"; "disconnected fragments of a story"; "scattered
           thoughts" [syn: confused, disconnected, disjointed,
           disordered, garbled, illogical, scattered,
           unconnected]