[1] : The Collaborative International Dictionary of English v.0.48

flatten \flat"ten\, v. i.
   to become or grow flat, even, depressed, dull, vapid,
   spiritless, or depressed below pitch.
   1913 webster

[2] : The Collaborative International Dictionary of English v.0.48

flatten \flat"ten\ fla^t"t'n, v. t. imp.  p. p.
   flattened; p. pr.  vb. n. flattening. from flat, a.
   1. to reduce to an even surface or one approaching evenness;
      to make flat; to level; to make plane.
      1913 webster

   2. to throw down; to bring to the ground; to prostrate;
      hence, to depress; to deject; to dispirit.
      1913 webster

   3. to make vapid or insipid; to render stale.
      1913 webster

   4. mus. to lower the pitch of; to cause to sound less
      sharp; to let fall from the pitch.
      1913 webster

   to flatten a sail naut., to set it more nearly
      fore-and-aft of the vessel.

   flattening oven, in glass making, a heated chamber in which
      split glass cylinders are flattened for window glass.
      1913 webster
see also:
flattened flattening flat to flatten a sail flattening oven 

[3] : WordNet (r) 2.0

flatten
     v 1: make flat or flatter; "flatten a road"; "flatten your
          stomach with these exercises"
     2: become flat or flatter; "the landscape flattened" syn: flatten
        out
     3: lower the pitch of musical notes syn: drop ant: sharpen
see also:
flatten out drop sharpen 

[4] : Moby Thesaurus II by Grady Ward, 1.0

108 moby thesaurus words for "flatten":
   align, assimilate to, balance, beat down, bend, blow down, break,
   break down, bring down, bulldoze, burn down, cast down, chop down,
   conquer, crush, cut down, dab, damp, demolish, disentangle, down,
   drag, dress, dub, equalize, equilibrize, even, extend, fell, floor,
   flush, grade, grease, ground, harmonize, harrow, homogenize,
   humble, knock, knock down, knock out, knock over, lay, lay down,
   lay flat, lay level, lay low, lay out, level, lubricate,
   make uniform, master, mow, mow down, normalize, oil, override,
   plane, planish, plaster, press out, prostrate, pull down, put down,
   put straight, quell, rase, raze, rectify, reduce, regularize,
   regulate, ride down, roll, roll flat, set straight, shave, sit up,
   smash, smooth, smooth down, smooth out, smoothen, stabilize,
   stand up, standardize, steamroll, steamroller, stereotype,
   straighten, straighten out, straighten up, subdue, subjugate,
   suppress, symmetrize, take down, tear down, throw down,
   trample down, trample underfoot, tread underfoot, unbend, uncurl,
   uniformize, unkink, unsnarl, vanquish

[5] : Jargon File (4.3.1, 29 Jun 2001)

flatten vt. common to remove structural information, esp. to filter
   something with an implicit tree structure into a simple sequence of
   leaves; also tends to imply mapping to flat-ascii. "this code flattens
   an expression with parentheses into an equivalent canonical form."


see also:
flat-ascii canonical 

[6] : The Free On-line Dictionary of Computing (27 SEP 03)

flatten
     
        to remove structural information, especially to filter
        something with an implicit tree structure into a simple
        sequence of leaves; also tends to imply mapping to
        flat ascii.  "this code flattens an expression with
        parentheses into an equivalent canonical form."
     
        jargon file
     
     
see also:
flat ascii canonical jargon file 

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