The Collaborative International Dictionary of English v.0.48:

Conquest \Con"quest\, n. [OF. conquest, conqueste, F.
   conqu[^e]te, LL. conquistum, conquista, prop. p. p. from L.
   conquirere. See Conquer.]
   1. The act or process of conquering, or acquiring by force;
      the act of overcoming or subduing opposition by force,
      whether physical or moral; subjection; subjugation;
      victory.
      [1913 Webster]

            In joys of conquest he resigns his breath.
                                                  --Addison.
      [1913 Webster]

            Three years sufficed for the conquest of the
            country.                              --Prescott.
      [1913 Webster]

   2. That which is conquered; possession gained by force,
      physical or moral.
      [1913 Webster]

            Wherefore rejoice? What conquest brings he home?
                                                  --Shak.
      [1913 Webster]

   3. (Feudal Law) The acquiring of property by other means than
      by inheritance; acquisition. --Blackstone.
      [1913 Webster]

   4. The act of gaining or regaining by successful struggle;
      as, the conquest of liberty or peace.
      [1913 Webster]

   The Conquest (Eng. Hist.), the subjugation of England by
      William of Normandy in 1066. The Norman Conquest.

   Syn: Victory; triumph; mastery; reduction; subjugation;
        subjection.
        [1913 Webster]

WordNet (r) 3.0 (2006):

conquest
    n 1: the act of conquering [syn: conquest, conquering,
         subjection, subjugation]
    2: success in mastering something difficult; "the conquest of
       space"
    3: an act of winning the love or sexual favor of someone [syn:
       seduction, conquest]

Moby Thesaurus II by Grady Ward, 1.0:

88 Moby Thesaurus words for "conquest":
   Cadmean victory, KO, Pyrrhic victory, Waterloo, adoption,
   appropriation, arrogation, ascendancy, assumption, beating,
   captive, catch, championship, collapse, colonization, conquering,
   coquette, crash, date, deathblow, debacle, defeat, defeating,
   destruction, domination, downfall, drubbing, easy victory,
   enslavement, failure, fall, flirt, grand slam, hiding, honey,
   indent, knockout, lambasting, landslide, landslide victory,
   lathering, licking, mastery, moral victory, occupation, overcoming,
   overthrow, overturn, picnic, preemption, preoccupation,
   prepossession, pushover, quietus, requisition, rout, routing, ruin,
   runaway victory, smash, steady, subdual, subduing, subjection,
   subjugation, success, sweet patootie, sweetheart, sweetie,
   takeover, taking over, thrashing, total victory, trimming, triumph,
   trouncing, undoing, usurpation, vamp, vampire, vanquishment,
   victory, walkaway, walkover, whipping, win, winning,
   winning streak



Bouvier's Law Dictionary, Revised 6th Ed (1856):

CONQUEST, feudal law. This term was used by the feudists to signify
purchase.



Bouvier's Law Dictionary, Revised 6th Ed (1856):

CONQUEST, international law. The acquisition of the sovereignty of a country
by force of arms, exercised by an independent power which reduces the
vanquished to the submission of its empire.
     2. It is a general rule, that where conquered countries have laws of
their own, these laws remain in force after the conquest, until they are
abrogated, unless they are contrary to our religion, or enact any malum in
se. In all such cases the laws of the conquering country prevail; for it is
not to be presumed that laws opposed to religion or sound morals could be
sanctioned. 1 Story, Const. Sec. 150, and the cases there cited.
     3. The conquest and military occupation of a part of the territory of
the United States by a public enemy, renders such conquered territory,
during such occupation, a foreign country with respect to the revenue laws
of the United States. 4 Wheat. R. 246; 2 Gallis. R. 486. The people of a
conquered territory change their allegiance, but, by the modern practice,
their relations to each other, and their rights of property, remain the
same. 7 Pet. R. 86.
     4. Conquest does not, per se, give the conqueror plenum dominium et
utile, but a temporary right of possession and government. 2 Gallis. R. 486;
3 Wash. C. C. R. 101. See 8 Wheat. R. 591; 2 Bay, R. 229; 2 Dall. R. 1; 12
Pet. 410.
     5. The right which the English government claimed over the territory
now composing the United States, was not founded on conquest, but discovery.
Id. Sec. 152, et seq.