Dictionary.com
Thesaurus.com
Showing results for which is which. Search instead for which+is+which.

which is which

Idioms  
  1. What particular one is what particular one, or what is the difference between different ones. For example, These twins look so much alike I can't tell which is which, or Both our raincoats are tan; do you know which is which? This idiom was first recorded about 1412.