The Collaborative International Dictionary of English v.0.48:

Descent \De*scent"\, n. [F. descente, fr. descendre; like vente,
   from vendre. See Descend.]
   1. The act of descending, or passing downward; change of
      place from higher to lower.
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   2. Incursion; sudden attack; especially, hostile invasion
      from sea; -- often followed by upon or on; as, to make a
      descent upon the enemy.
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            The United Provinces . . . ordered public prayer to
            God, when they feared that the French and English
            fleets would make a descent upon their coasts.
                                                  --Jortin.
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   3. Progress downward, as in station, virtue, as in station,
      virtue, and the like, from a higher to a lower state, from
      a higher to a lower state, from the more to the less
      important, from the better to the worse, etc.
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   2. Derivation, as from an ancestor; procedure by generation;
      lineage; birth; extraction. --Dryden.
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   5. (Law) Transmission of an estate by inheritance, usually,
      but not necessarily, in the descending line; title to
      inherit an estate by reason of consanguinity. --Abbott.
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   6. Inclination downward; a descending way; inclined or
      sloping surface; declivity; slope; as, a steep descent.
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   7. That which is descended; descendants; issue.
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            If care of our descent perplex us most,
            Which must be born to certain woe.    --Milton.
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   8. A step or remove downward in any scale of gradation; a
      degree in the scale of genealogy; a generation.
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            No man living is a thousand descents removed from
            Adam himself.                         --Hooker.
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   9. Lowest place; extreme downward place. [R.]
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            And from the extremest upward of thy head,
            To the descent and dust below thy foot. --Shak.

   10. (Mus.) A passing from a higher to a lower tone.

   Syn: Declivity; slope; degradation; extraction; lineage;
        assault; invasion; attack.
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WordNet (r) 3.0 (2006):

descent
    n 1: a movement downward
    2: properties attributable to your ancestry; "he comes from good
       origins" [syn: origin, descent, extraction]
    3: the act of changing your location in a downward direction
    4: the kinship relation between an individual and the
       individual's progenitors [syn: descent, line of descent,
       lineage, filiation]
    5: a downward slope or bend [syn: descent, declivity,
       fall, decline, declination, declension, downslope]
       [ant: acclivity, ascent, climb, raise, rise,
       upgrade]
    6: the descendants of one individual; "his entire lineage has
       been warriors" [syn: lineage, line, line of descent,
       descent, bloodline, blood line, blood, pedigree,
       ancestry, origin, parentage, stemma, stock]