The Collaborative International Dictionary of English v.0.48:

Sire \Sire\, v. t. [imp. & p. p. Sired; p. pr. & vb. n.
   Siring.]
   To beget; to procreate; -- used of beasts, and especially of
   stallions.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sire \Sire\, n. [F. sire, originally, an older person. See
   Sir.]
   1. A lord, master, or other person in authority. See Sir.
      [Obs.]
      [1913 Webster]

            Pain and distress, sickness and ire,
            And melancholy that angry sire,
            Be of her palace senators.            --Rom. of R.
      [1913 Webster]

   2. A tittle of respect formerly used in speaking to elders
      and superiors, but now only in addressing a sovereign.
      [1913 Webster]

   3. A father; the head of a family; the husband.
      [1913 Webster]

            Jankin thet was our sire [i.e., husband]. --Chaucer.
      [1913 Webster]

            And raise his issue, like a loving sire. --Shak.
      [1913 Webster]

   4. A creator; a maker; an author; an originator.
      [1913 Webster]

            [He] was the sire of an immortal strain. --Shelley.
      [1913 Webster]

   5. The male parent of a beast; -- applied especially to
      horses; as, the horse had a good sire.
      [1913 Webster]

   Note: Sire is often used in composition; as in grandsire,
         grandfather; great-grandsire, great-grandfather.
         [1913 Webster]

WordNet (r) 3.0 (2006):

sire
    n 1: a title of address formerly used for a man of rank and
         authority
    2: the founder of a family; "keep the faith of our forefathers"
       [syn: forefather, father, sire]
    3: male parent of an animal especially a domestic animal such as
       a horse
    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:

145 Moby Thesaurus words for "sire":
   Esquire, Master, Mister, Sir, abba, agent, ancestors, apprentice,
   architect, artificer, artist, author, bear, beget, begetter,
   beginner, birth, breed, breed true, bring about, bring forth,
   bring to birth, bring to effect, bring to pass, builder, catalyst,
   cause, causer, conceive, conceiver, constructor, copulate,
   craftsman, create, creator, crossbreed, dad, daddy, dean, designer,
   deviser, discoverer, do, doyen, doyenne, effect, effector,
   effectuate, effendi, elder, eldest, emir, engender, engenderer,
   engineer, establish, executor, executrix, father, first-born,
   firstling, foster father, found, founder, generate, generator,
   genitor, gestate, get, give birth to, give occasion to,
   give origin to, give rise to, governor, grower, hatch, inaugurate,
   inaugurator, inbreed, industrialist, initiator, inspirer,
   instigator, institute, institutor, introducer, inventor,
   journeyman, khan, make, make love, maker, manufacturer, master,
   master craftsman, mirza, mother, mover, multiply, occasion, older,
   oldest, organizer, originate, originator, outbreed, pa, pap, papa,
   pappy, parent, past master, pater, paterfamilias, patriarch,
   planner, pop, pops, precursor, prime mover, primum mobile,
   procreate, produce, producer, progenerate, proliferate, propagate,
   raiser, realize, realizer, reproduce in kind, sahib, senior,
   set afloat, set on foot, set up, shaper, sirdar, sirrah, smith,
   spawn, stepfather, the old man, work, wright