The Collaborative International Dictionary of English v.0.48:

Debase \De*base"\, v. t. [imp. & p. p. Debased; p. pr. & vb.
   n. Debasing.] [Pref. de- + base. See Base, a., and cf.
   Abase.]
   To reduce from a higher to a lower state or grade of worth,
   dignity, purity, station, etc.; to degrade; to lower; to
   deteriorate; to abase; as, to debase the character by crime;
   to debase the mind by frivolity; to debase style by vulgar
   words.
   [1913 Webster]

         The coin which was adulterated and debased. --Hale.
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         It is a kind of taking God's name in vain to debase
         religion with such frivolous disputes.   --Hooker.
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         And to debase the sons, exalts the sires. --Pope.

   Syn: To abase; degrade. See Abase.
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The Collaborative International Dictionary of English v.0.48:

Debased \De*based"\, a. (Her.)
   Turned upside down from its proper position; inverted;
   reversed.
   [1913 Webster]

WordNet (r) 3.0 (2006):

debased
    adj 1: mixed with impurities [syn: adulterate, adulterated,
           debased]
    2: lowered in value; "the dollar is low"; "a debased currency"
       [syn: debased, devalued, degraded]
    3: ruined in character or quality [syn: corrupted, debased,
       vitiated]