muddle up vs set apart

muddle up

verb
  • to confuse (one or more objects with another object or other objects) 

  • To mix together 

set apart

verb
  • To distinguish, make obvious the distinction between (two things) or of (something). 

  • Used other than figuratively or idiomatically: to separate or isolate. 

  • To select (something or someone) for a specific purpose. 

How often have the words muddle up and set apart occurred in a corpus of books? (source: Google Ngram Viewer )