NOUN (1)

1. the property possessed by a slope or surface that descends;


VERB (1)

1. rate lower; lower in value or esteem;

WordNet (r) 3.0 (2006):

downgrade
    n 1: the property possessed by a slope or surface that descends
    v 1: rate lower; lower in value or esteem [ant: upgrade]

Moby Thesaurus II by Grady Ward, 1.0:

149 Moby Thesaurus words for "downgrade":
   abase, abridge, adown, aslant, aslantwise, aslope, at a slant,
   atilt, atrophy, belittle, below, break, bump, bust, cascade,
   cataract, chute, collapse, comedown, compress, crash, curtail, cut,
   cut back, cut down, damp, dampen, debacle, debase, decadence,
   declension, declination, decline, declined, declining, declivate,
   declivitous, declivity, declivous, decrease, decry, deduct,
   deflate, defluxion, degeneracy, degeneration, degrade, demerit,
   demote, denigrate, deplume, depose, depreciate, depress,
   descending, descension, descent, dethrone, devalue, devolution,
   diminish, dip, dipping, disenfranchise, disfranchise, disgrade,
   disparage, displace, displume, dispossess, down, down south,
   downbend, downcome, downcurve, downfall, downflow, downgate,
   downhill, downline, downplay, downpour, downright, downrush,
   downstairs, downstream, downstreet, downtown, downtrend, downturn,
   downward, downward trend, downwards, downwith, drop, dropping,
   fall, falling, falling off, falling-off, grade, gradient,
   gravitation, hang, hanging, humble, inclination, lessen, lower,
   mark down, minimize, off plumb, on the downgrade, on the skids,
   on the wane, pare, play down, plummeting, pounce, rakingly, rapids,
   reduce, retrench, roll back, run down, scale down, shorten,
   simplify, slantingly, slantways, slantwise, slaunchways, slipping,
   slopeways, slopingly, step down, stoop, strip of rank, swoop,
   take from, tipsily, tune down, undervalue, upgrade, uphill, waning,
   waterfall, write down, write off