Mixing public/business affairs with private/personal matters; failing to separate professional duties from personal interests.
上司が特定の部下を贔屓するのは公私混同だ。
A boss favoring a particular subordinate is a case of mixing public and private matters.
公私混同を避けるために、利益相反の申告が必要だ。
To avoid mixing public and private affairs, declaration of conflicts of interest is necessary.
会社の資金を私的に使うのは明らかな公私混同だ。
Using company funds for personal purposes is clearly mixing business with private matters.