The Collaborative International Dictionary of English v.0.48:

improved \improved\ adj.
   1. advanced to a more desirable or valuable or excellent
      state. Opposite of unimproved. [Narrower terms: built,
      reinforced; cleared, tilled ; {developed; grade ;
      {graded, graveled ] Also See: {restored.
      [WordNet 1.5]

   2. changed for the better; as, her improved behavior.

   Syn: amended.
        [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

Develop \De*vel"op\ (d[-e]*v[e^]l"[o^]p), v. t. [imp. & p. p.
   Developed; p. pr. & vb. n. Developing.] [F. d['e]veloper;
   d['e]- (L. dis-) + OF. voluper, voleper, to envelop, perh.
   from L. volup agreeably, delightfully, and hence orig., to
   make agreeable or comfortable by enveloping, to keep snug
   (cf. Voluptuous); or. perh. fr. a derivative of volvere,
   volutum, to roll (cf. Devolve). Cf. Envelop.] [Written
   also develope.]
   1. To free from that which infolds or envelops; to unfold; to
      lay open by degrees or in detail; to make visible or
      known; to disclose; to produce or give forth; as, to
      develop theories; a motor that develops 100 horse power.
      [1913 Webster]

            These serve to develop its tenets.    --Milner.
      [1913 Webster]

            The 20th was spent in strengthening our position and
            developing the line of the enemy.     --The Century.
      [1913 Webster]

   2. To unfold gradually, as a flower from a bud; hence, to
      bring through a succession of states or stages, each of
      which is preparatory to the next; to form or expand by a
      process of growth; to cause to change gradually from an
      embryo, or a lower state, to a higher state or form of
      being; as, sunshine and rain develop the bud into a
      flower; to develop the mind.
      [1913 Webster]

            The sound developed itself into a real compound.
                                                  --J. Peile.
      [1913 Webster]

            All insects . . . acquire the jointed legs before
            the wings are fully developed.        --Owen.
      [1913 Webster]

   3. To advance; to further; to prefect; to make to increase;
      to promote the growth of.
      [1913 Webster]

            We must develop our own resources to the utmost.
                                                  --Jowett
                                                  (Thucyd).
      [1913 Webster]

   4. (Math.) To change the form of, as of an algebraic
      expression, by executing certain indicated operations
      without changing the value.
      [1913 Webster]

   5. (Photog.) To cause to become visible, as an invisible or
      latent image upon plate, by submitting it to chemical
      agents; to bring to view.
      [1913 Webster]

   To develop a curved surface on a plane (Geom.), to produce
      on the plane an equivalent surface, as if by rolling the
      curved surface so that all parts shall successively touch
      the plane.

   Syn: To uncover; unfold; evolve; promote; project; lay open;
        disclose; exhibit; unravel; disentangle.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

developed \developed\ adj.
   1. being changed over time so as to be e.g. stronger or more
      complete or more useful; as, the developed qualities of
      the Hellenic outlook; the state's well-developed
      industries. Oppositre of undeveloped. [Narrower terms:
      formulated; mature]
      [WordNet 1.5]

   2. made more useful and profitable as by building or laying
      out roads; -- of real estate. new houses are springing up
      on the developed tract of land near the river

   Syn: improved.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

developed
    adj 1: being changed over time so as to be e.g. stronger or more
           complete or more useful; "the developed qualities of the
           Hellenic outlook"; "they have very small limbs with only
           two fully developed toes on each" [ant: undeveloped]
    2: (used of societies) having high industrial development;
       "developed countries" [syn: developed, highly-developed]
    3: (of real estate) made more useful and profitable as by
       building or laying out roads; "condominiums were built on the
       developed site"

Moby Thesaurus II by Grady Ward, 1.0:

73 Moby Thesaurus words for "developed":
   advanced, aged, ameliorated, archetypical, beautified, bettered,
   blooming, blossoming, budding, burgeoning, civilized, classic,
   complete, consummate, converted, crescent, cultivated, cultured,
   educated, embellished, enhanced, enriched, entire, exemplary,
   expert, finished, florescent, flourishing, flowering, full,
   full-blown, full-fledged, full-grown, full-scale, fully developed,
   global, growing, grown, grown-up, hypertrophied, improved,
   in full bloom, intact, masterful, masterly, mature, matured,
   mellow, mellowed, model, overdeveloped, overgrown, perfected,
   polished, proficient, quintessential, refined, reformed, ripe,
   ripened, seasoned, solid, sprouting, tempered, thriving, total,
   transfigured, transformed, unabbreviated, uncut, undiminished,
   unexpurgated, whole