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.]
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   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]