Source : Webster's Revised Unabridged Dictionary (1913)

Sift \Sift\, v. t. [imp. & p. p. {Sifted}; p. pr. & vb. n.
   {Sifting}.] [AS. siftan, from sife sieve. [root]151a. See
   {Sieve}.]
   1. To separate with a sieve, as the fine part of a substance
      from the coarse; as, to sift meal or flour; to sift
      powder; to sift sand or lime.

   2. To separate or part as if with a sieve.

            When yellow sands are sifted from below, The
            glittering billows give a golden show. --Dryden.

   3. To examine critically or minutely; to scrutinize.

            Sifting the very utmost sentence and syllable.
                                                  --Hooker.

            Opportunity I here have had To try thee, sift thee.
                                                  --Milton.

            Let him but narrowly sift his ideas.  --I. Taylor.

   {To sift out}, to search out with care, as if by sifting.

Source : WordNet®

sift
     v 1: move as if through a sieve; "The soldiers sifted through the
          woods"
     2: separate by passing through a sieve or other straining
        device to separate out coarser elements; "sift the flour"
        [syn: {sieve}, {strain}]
     3: check and sort carefully; "sift the information" [syn: {sieve}]
     4: distinguish and separate out; "sift through the job
        candidates" [syn: {sieve}]

Source : Free On-Line Dictionary of Computing

SIFT
     
        SHARE Internal Fortran Translator.  Translation utility
        designed for converting Fortran II to Fortran IV.  The word
        "sift" was often used as a verb to describe converting code
        from one language to another.  Sammet 1969, p.153.