The Collaborative International Dictionary of English v.0.48:

Beget \Be*get"\, v. t. [imp. Begot, (Archaic) Begat; p. p.
   Begot, Begotten; p. pr. & vb. n. Begetting.] [OE.
   bigiten, bigeten, to get, beget, AS. begitan to get; pref.
   be- + gitan. See Get, v. t. ]
   1. To procreate, as a father or sire; to generate; --
      commonly said of the father.
      [1913 Webster]

            Yet they a beauteous offspring shall beget.
                                                  --Milton.
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   2. To get (with child.) [Obs.] --Shak.
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   3. To produce as an effect; to cause to exist.
      [1913 Webster]

            Love is begot by fancy.               --Granville.
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WordNet (r) 3.0 (2006):

beget
    v 1: make children; "Abraham begot Isaac"; "Men often father
         children but don't recognize them" [syn: beget, get,
         engender, father, mother, sire, generate, bring
         forth]

Moby Thesaurus II by Grady Ward, 1.0:

83 Moby Thesaurus words for "beget":
   author, be fruitful, be productive, bear, birth, breed, breed true,
   bring about, bring forth, bring into being, bring to birth,
   bring to effect, bring to pass, call into being, cause, coin,
   conceive, concoct, contrive, cook up, copulate, create, crossbreed,
   design, develop, devise, discover, do, dream up, effect,
   effectuate, engender, establish, evolve, fabricate, father, found,
   frame, fructify, generate, gestate, get, give being to,
   give birth to, give occasion to, give origin to, give rise to,
   hatch, improvise, inaugurate, inbreed, institute, invent, make,
   make do with, make love, make up, mature, mint, mother, multiply,
   occasion, originate, outbreed, plan, procreate, produce,
   proliferate, propagate, pullulate, realize, reproduce,
   reproduce in kind, set afloat, set on foot, set up, sire, spawn,
   strike out, teem, think out, think up, work