Professor Adrian Keane, in his 9th Edition of the Modern Law of Evidence, defines hearsay in the reverse as ‘any assertion made by a person other than by one who gives oral evidence in the proceedings if tendered as evidence of the facts asserted’.
In other words, any testimony given by a witness concerning words spoken, statements made or documents generated by a person who is not produced in court as a witness if the testimony is presented to prove the truth of the facts which they assert.