The Collaborative International Dictionary of English v.0.48:

Dispraise \Dis*praise"\, v. t. [imp. & p. p. Dispraised; p.
   pr. & vb. n. Dispraising.] [OE. dispreisen, OF. desprisier,
   despreisier, F. d['e]priser; pref. des- (L. dis-) + prisier,
   F. priser, to prize, praise. See Praise, and cf.
   Disprize, Depreciate.]
   To withdraw praise from; to notice with disapprobation or
   some degree of censure; to disparage; to blame.
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         Dispraising the power of his adversaries. --Chaucer.
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         I dispraised him before the wicked, that the wicked
         might not fall in love with him.         --Shak.
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The Collaborative International Dictionary of English v.0.48:

Dispraise \Dis*praise"\, n. [Cf. OF. despris. See Dispraise,
   v. t.]
   The act of dispraising; detraction; blame censure; reproach;
   disparagement. --Dryden.
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         In praise and in dispraise the same.     --Tennyson.
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WordNet (r) 3.0 (2006):

dispraise
    n 1: the act of speaking contemptuously of [syn:
         disparagement, dispraise]