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.
      [1913 Webster]

   2. Incursion; sudden attack; especially, hostile invasion
      from sea; -- often followed by upon or on; as, to make a
      descent upon the enemy.
      [1913 Webster]

            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.
      [1913 Webster]

   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.
      [1913 Webster]

   2. Derivation, as from an ancestor; procedure by generation;
      lineage; birth; extraction. --Dryden.
      [1913 Webster]

   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.
      [1913 Webster]

   6. Inclination downward; a descending way; inclined or
      sloping surface; declivity; slope; as, a steep descent.
      [1913 Webster]

   7. That which is descended; descendants; issue.
      [1913 Webster]

            If care of our descent perplex us most,
            Which must be born to certain woe.    --Milton.
      [1913 Webster]

   8. A step or remove downward in any scale of gradation; a
      degree in the scale of genealogy; a generation.
      [1913 Webster]

            No man living is a thousand descents removed from
            Adam himself.                         --Hooker.
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   9. Lowest place; extreme downward place. [R.]
      [1913 Webster]

            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.
        [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

309 Moby Thesaurus words for "descent":
   Brownian movement, Indian file, abasement, advance, affiliation,
   altitude peak, angular motion, apparentation, array, articulation,
   ascending, ascent, automatic control, axial motion, backflowing,
   backing, backset, backward motion, bank, birth, blast-off, blood,
   bloodline, branch, breed, brood, burn, burnout, buzz, career,
   catena, catenation, ceiling, chain, chain reaction, chaining,
   characterize, check, children, climbing, comedown, coming after,
   common ancestry, communicate, concatenation, concavity, connection,
   consanguinity, consecution, consecutiveness, construe,
   continuation, continuity, continuum, course, current, cycle,
   de-escalation, debasement, decadence, decadency, declension,
   declination, decline, declivity, deflation, deformation,
   degeneracy, degenerateness, degeneration, degradation, delineate,
   demotion, depict, depravation, depravedness, depreciation,
   depression, derivation, derogation, descendants, descending,
   describe, deterioration, detrusion, devolution, diminution, dip,
   direct line, discomfiture, disgrace, distaff side, distinguish,
   down, downgate, downgrade, downhill, downtrend, downturn,
   downward mobility, downward motion, downward trend, drift,
   driftage, drone, drop, ducking, dump, dying, ebb, ebbing,
   effeteness, elucidate, embarrassment, end of burning, endless belt,
   endless round, exemplify, explain, explicate, expound, extension,
   extraction, fading, failing, failure, failure of nerve, fall,
   falling-off, family, female line, file, filiation, flight, flow,
   flux, following, forward motion, fruit, gamut, gradation, grade,
   gradient, grandchildren, great-grandchildren, hang, hangdog look,
   hanging, hauling down, heirs, hollowness, hostages to fortune,
   house, hum, humbled pride, humiliation, ignition, illustrate,
   image, impact, impart, incline, inheritors, interpret, involution,
   issue, kids, lapse, launch, letdown, lift-off, limn, line,
   line of descent, lineage, little ones, logical sequence,
   loss of tone, lowering, male line, monotone, mortification,
   mounting, narrate, new generation, nexus, oblique motion,
   offspring, ongoing, onrush, order, order of succession, origin,
   passage, pedigree, pendulum, periodicity, phylum, picture, plenum,
   plummeting, plunging, portray, posteriority, posterity,
   postposition, powder train, procession, progeny, progress,
   progression, prolongation, put-down, queue, race, radial motion,
   random motion, range, rank, recite, recount, recurrence, reduction,
   reflowing, refluence, reflux, regression, rehearse, render, report,
   reticulation, retrocession, retrogradation, retrogression,
   reversal, reverse, reverse of fortune, rise, rising,
   rising generation, rocket launching, rotation, round, routine, row,
   run, rush, scale, seed, self-abasement, self-abnegation,
   self-diminishment, sept, sequence, series, set, setback, setdown,
   severe check, shame, shamefacedness, shamefastness, shoot, shot,
   side, sideward motion, single file, sinking, slippage, slope,
   slump, soaring, sons, spear side, spectrum, spindle side, state,
   stem, sternway, stirps, stock, strain, stream, string, subjunction,
   submergence, subsiding, succession, successiveness, suffixation,
   swath, sword side, thread, throwback, thrusting under, tier, train,
   traject, trajectory, trajet, transmit, treasures, trend,
   upward motion, velocity peak, wane, windrow, younglings,
   youngsters