The Collaborative International Dictionary of English v.0.48:

Expand \Ex*pand"\, v. t. [imp. & p. p. Expanded; p. pr. & vb.
   n. Expanding.] [L. expandere, expansum; ex out + pandere to
   spread out, to throw open; perh. akin to E. patent. Cf.
   Spawn.]
   1. To lay open by extending; to open wide; to spread out; to
      diffuse; as, a flower expands its leaves.
      [1913 Webster]

            Then with expanded wings he steers his flight.
                                                  --Milton.
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   2. To cause the particles or parts of to spread themselves or
      stand apart, thus increasing bulk without addition of
      substance; to make to occupy more space; to dilate; to
      distend; to extend every way; to enlarge; -- opposed to
      contract; as, to expand the chest; heat expands all
      bodies; to expand the sphere of benevolence.
      [1913 Webster]

   3. (Math.) To state in enlarged form; to develop; as, to
      expand an equation. See Expansion, 5.
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The Collaborative International Dictionary of English v.0.48:

Expanding \Ex*pand"ing\, a.
   That expands, or may be expanded; extending; spreading;
   enlarging.
   [1913 Webster]

   Expanding bit, Expanding drill (Mech.), a bit or drill
      made adjustable for holes of various sizes; one which can
      be expanded in diameter while boring.

   Expanding pulley (Mach.), a pulley so made, as in sections,
      that its diameter can be increased or diminished.
      [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

21 Moby Thesaurus words for "expanding":
   amplifying, crescendoing, crescent, developmental, dilatative,
   dilative, enlarging, expatiating, growing, increasing, incremental,
   intensifying, lengthening, multiplying, on the increase,
   proliferating, snowballing, spreading, swelling, tightening,
   waxing