The Collaborative International Dictionary of English v.0.48:

Extend \Ex*tend"\ ([e^]ks*t[e^]nd"), v. t. [imp. & p. p.
   Extended; p. pr. & vb. n. Extending.] [L. extendere,
   extentum, extensum; ex out + tendere to stretch. See
   Trend.]
   1. To stretch out; to prolong in space; to carry forward or
      continue in length; as, to extend a line in surveying; to
      extend a cord across the street.
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            Few extend their thoughts toward universal
            knowledge.                            --Locke.
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   2. To enlarge, as a surface or volume; to expand; to spread;
      to amplify; as, to extend metal plates by hammering or
      rolling them.
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   3. To enlarge; to widen; to carry out further; as, to extend
      the capacities, the sphere of usefulness, or commerce; to
      extend power or influence; to continue, as time; to
      lengthen; to prolong; as, to extend the time of payment or
      a season of trial.
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   4. To hold out or reach forth, as the arm or hand.
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            His helpless hand extend.             --Dryden.
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   5. To bestow; to offer; to impart; to apply; as, to extend
      sympathy to the suffering.
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   6. To increase in quantity by weakening or adulterating
      additions; as, to extend liquors. --G. P. Burnham.
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   7. (Eng. Law) To value, as lands taken by a writ of extent in
      satisfaction of a debt; to assign by writ of extent.
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   Extended letter (Typog.), a letter, or style of type,
      having a broader face than is usual for a letter or type
      of the same height.
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   Note: This is extended type.

   Syn: To increase; enlarge; expand; widen; diffuse. See
        Increase.
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WordNet (r) 3.0 (2006):

extended
    adj 1: relatively long in duration; tediously protracted; "a
           drawn-out argument"; "an extended discussion"; "a lengthy
           visit from her mother-in-law"; "a prolonged and bitter
           struggle"; "protracted negotiations" [syn: drawn-out,
           extended, lengthy, prolonged, protracted]
    2: fully extended or stretched forth; "an extended telescope";
       "his extended legs reached almost across the small room";
       "refused to accept the extended hand" [ant: unextended]
    3: drawn out or made longer spatially; "Picasso's elongated Don
       Quixote"; "lengthened skirts are fashionable this year"; "the
       extended airport runways can accommodate larger planes"; "a
       prolonged black line across the page" [syn: elongated,
       extended, lengthened, prolonged]
    4: beyond the literal or primary sense; "`hot off the press'
       shows an extended sense of `hot'"
    5: large in spatial extent or range or scope or quantity; "an
       extensive Roman settlement in northwest England"; "extended
       farm lands"; "surgeons with extended experience"; "they
       suffered extensive damage" [syn: extensive, extended]

Moby Thesaurus II by Grady Ward, 1.0:

135 Moby Thesaurus words for "extended":
   accelerated, aggrandized, allegorical, ample, ampliate, amplified,
   amplitudinous, associational, augmented, beefed-up, bloated,
   boosted, broad, broadened, built-up, capacious, commodious,
   connotational, connotative, crescendoed, de longue haleine, deep,
   deepened, definable, denotational, denotative, dragged out, drawn,
   drawn out, drawn-out, elevated, elongate, elongated, endless,
   enhanced, enlarged, expanded, expansive, expressive, extending,
   extensional, extensive, far-flung, far-reaching, figurative,
   filled out, full of meaning, full of point, full of substance,
   heightened, hiked, increased, indicative, infinite, inflated,
   intelligible, intensified, intensional, interminable,
   interpretable, jazzed up, languishing, lasting, lengthened,
   lengthy, lingering, long, long-continuing, long-drawn,
   long-drawn-out, long-pending, long-spun, long-winded, longiloquent,
   magnified, marathon, meaning, meaningful, meaty, metaphorical,
   multiplied, overlong, padded, pithy, pointed, pregnant,
   proliferated, prolix, prolongated, prolonged, protracted, pulled,
   raised, readable, referential, reinforced, roomy, scopic,
   sententious, significant, significative, spacious, spread,
   spread out, spreading, spun out, spun-out, stiffened, straggling,
   strained, strengthened, stretched, stretched out, stretched-out,
   strung out, substantial, suggestive, swollen, symbolic, talkative,
   taut, tense, tight, tightened, transferred, unrelenting, upped,
   vast, verbose, voluminous, wide, widened, widespread, windy,
   wordy