That's the truth! (6)
(Other definitions for honest that I've seen before include "Free from guile" , "Straight up" , "Trustworthy or candid" , "really!" , "Frank" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">that's the truth</span>' is the definition.<br/ ><span class="explanation-format__explanation">(true facts)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for fact that I've seen before include "Certain thing" , "Item of truth" , "Something known to be true" , "Actuality" , "True item; reality" .)