Source : Webster's Revised Unabridged Dictionary (1913)

Crunch \Crunch\ (kr[u^]nch), v. i. [imp. & p. p. {Crunched}
   (kr[u^]ncht); p. pr. & vb. n. {Crunching}.] [Prob. of
   imitative origin; or cf. D. schransen to eat heartily, or E.
   scrunch.]
   1. To chew with force and noise; to craunch.

            And their white tusks crunched o'er the whiter
            skull.                                --Byron.

   2. To grind or press with violence and noise.

            The ship crunched through the ice.    --Kane.

   3. To emit a grinding or craunching noise.

            The crunching and ratting of the loose stones. --H.
                                                  James.

Crunch \Crunch\, v. t.
   To crush with the teeth; to chew with a grinding noise; to
   craunch; as, to crunch a biscuit.

Source : WordNet®

crunch
     n 1: the sound of something crunching; "he heard the crunch of
          footsteps on the gravel path"
     2: a critical situation that arises because of a shortage (as a
        shortage of time or money or resources); "an end-of-the
        year crunch"; "a financial crunch"
     3: the act of crushing [syn: {crush}, {compaction}]
     v 1: make crunching noises; "his shoes were crunching on the
          gravel" [syn: {scranch}, {scraunch}, {crackle}]
     2: press or grind with a crunching noise [syn: {cranch}, {craunch},
         {grind}]
     3: chew noisily; "The children crunched the celery sticks"
        [syn: {munch}]
     4: reduce to small pieces or particles by pounding or abrading;
        "grind the spices in a mortar"; "mash the garlic" [syn: {grind},
         {mash}, {bray}, {comminute}]

Source : Free On-Line Dictionary of Computing

crunch
     
        1.  To process, usually in a time-consuming or
        complicated way.  Connotes an essentially trivial operation
        that is nonetheless painful to perform.  The pain may be due
        to the triviality's being embedded in a loop from 1 to
        1,000,000,000.  "Fortran programs do mostly {number
        crunching}."
     
        2.  To reduce the size of a file without losing
        information by a complicated scheme that produces bit
        configurations completely unrelated to the original data, such
        as by a {Huffman} code.  Since such {compression} usually
        takes more computations than simpler methods such as
        {run-length encoding}, the term is doubly appropriate.  (This
        meaning is usually used in the construction "file crunching"
        to distinguish it from {number crunching}.)  Use of {crunch}
        itself in this sense is rare among {Unix} hackers.
     
        3. The {hash character}.  Used at {XEROX} and {CMU}, among
        other places.
     
        4. To squeeze program source to the minimum size that will
        still compile or execute.  The term came from a {BBC
        Microcomputer} program that crunched {BBC BASIC} {source} in
        order to make it run more quickly (apart from storing
        {keywords} as byte codes, the language was wholly interpreted,
        so the number of characters mattered).  {Obfuscated C Contest}
        entries are often crunched; see the first example under that
        entry.
     
        [{Jargon File}]
     
        (2002-03-14)