Wordnet 3.0
NOUN (1)
1. 
 a mistake that results from taking one thing to be another; 
- Example: "he changed his name in order to avoid confusion with the notorious outlaw"[syn: confusion, mix-up]
The Collaborative International Dictionary of English v.0.48:
mix-up \mix-up\ n.
   a mistake that results from taking one thing to be another.
   Syn: confusion, confounding.
        [WordNet 1.5]
WordNet (r) 3.0 (2006):
mix-up
    n 1: a mistake that results from taking one thing to be another;
         "he changed his name in order to avoid confusion with the
         notorious outlaw" [syn: confusion, mix-up]