The term 'BLOW THE WHISTLE ON' is an idiom that means to reveal or EXPOSE something wrong or illegal. The crossword solutions for this term are TELL, EXPOSE, REF, RAT, and NAME. To 'TELL' something is to communicate it to someone else, while to 'EXPOSE' something is to make it known to the public. A 'REF' is a referee, who is responsible for making sure rules are followed in a game. To 'RAT' on someone is to inform on them, usually to an authority figure. Finally, to 'NAME' someone is to identify them as the perpetrator of a crime. All of these words can be used to describe the act of blowing the whistle on someone.