The Collaborative International Dictionary of English v.0.48:

Fulfill \Ful*fill"\, v. t. [imp. & p. p. Fulfilled; p. pr. &
   vb. n. Fulfilling.] [OE. fulfillen, fulfullen, AS.
   fulfyllan; ful full + fyllan to fill. See Full, a., and
   Fill, v. t.] [Written also fulfil.]
   1. To fill up; to make full or complete. [Obs.] "Fulfill her
      week" --Gen. xxix. 27.
      [1913 Webster]

            Suffer thou that the children be fulfilled first,
            for it is not good to take the bread of children and
            give to hounds.                       --Wyclif (Mark
                                                  vii. 27).
      [1913 Webster]

   2. To accomplish or carry into effect, as an intention,
      promise, or prophecy, a desire, prayer, or requirement,
      etc.; to complete by performance; to answer the
      requisitions of; to bring to pass, as a purpose or design;
      to effectuate.
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            He will, fulfill the desire of them fear him. --Ps.
                                                  cxlv. 199.
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            Here Nature seems fulfilled in all her ends.
                                                  --Milton.
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            Servants must their masters' minds fulfill. --Shak.
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WordNet (r) 3.0 (2006):

fulfil
    v 1: put in effect; "carry out a task"; "execute the decision of
         the people"; "He actioned the operation" [syn: carry
         through, accomplish, execute, carry out, action,
         fulfill, fulfil]
    2: fill or meet a want or need [syn: meet, satisfy, fill,
       fulfill, fulfil]
    3: meet the requirements or expectations of [syn: satisfy,
       fulfill, fulfil, live up to] [ant: fall short of]

Moby Thesaurus II by Grady Ward, 1.0:

32 Moby Thesaurus words for "fulfil":
   abide by, accomplish, achieve, answer, bring about, bring off,
   bring to completion, carry off, carry out, carry through,
   carry to completion, complete, comply with, conform to,
   conform with, consummate, discharge, do, effect, effectuate,
   execute, implement, keep, live up to, look to, meet, obey, observe,
   perform, realize, satisfy, see to