Completely accurate (5)
(Other definitions for errorless that I've seen before include "Correct" , "Perfect" .)
(Other definitions for spoton that I've seen before include "very accurate" , "Exactly!" , "precisely what is needed" , "precise" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">completely accurate</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for exact that I've seen before include "Spot-on" , "Specific" , "Absolutely accurate or correct" , "Explicit" , "Strict" .)