Last week, FBI Director Christopher Wray was asked about that characterization by the Attorney General - and he made clear that he did not agree with Barr, saying, "that's not the term I would use."
That semantic conflict was simmering in the President's mind, as he denounced the FBI Director's answer as 'ridiculous.'
"I thought the Attorney General answered it perfectly," Mr. Trump said of Wray. "I certainly didn't understand that answer; I thought it was a ridiculous answer."
In charge of the review will be U.S. Attorney John Durham of Connecticut - who is no stranger to high profile investigations.
In 2008, Durham was chosen to investigate the destruction of videotaped interrogations by the CIA, in a post-9/11 dispute over treatment of terrorist detainees, and whether they were tortured in violation of U.S. laws.
Last week, former FBI General Counsel Jim Baker said the probe began after Trump campaign foreign policy adviser George Papadopoulos told an Australian diplomat that Russia had offered to provide dirt on Hillary Clinton.
Papadopoulos later plead guilty to lying to investigators about his contacts with "certain foreign nationals whom he understood to have close connections with senior Russian government officials."