NOUN (1)

1. a bad or unsuitable match;


VERB (1)

1. match badly; match two objects or people that do not go together;

The Collaborative International Dictionary of English v.0.48:

Mismatch \Mis*match"\, v. t.
   To match unsuitably.
   [1913 Webster]

WordNet (r) 3.0 (2006):

mismatch
    n 1: a bad or unsuitable match
    v 1: match badly; match two objects or people that do not go
         together

Moby Thesaurus II by Grady Ward, 1.0:

40 Moby Thesaurus words for "mismatch":
   abnormality, agree to disagree, anomaly, be at cross-purposes,
   break, break off, clash, collide, conflict, contradict, counter,
   differ, disaccord, disagree, dissent, impropriety, inadmissibility,
   inapplicability, inappositeness, inappropriateness, inaptitude,
   inaptness, infelicity, irrelevance, irrelevancy, jangle, jar,
   jostle, maladjustment, mesalliance, misalliance, misjoinder,
   misjoining, mismate, negate, object, uncongeniality, unfitness,
   unsuitability, vary