Comprehensive, thorough (2-5)
I believe the answer is:
in-depth
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">comprehensive</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">thorough</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for in-depth that I've seen before include "Comprehensive and thorough" , "Thoroughly and comprehensively" , "Thorough and intensive" , "searching" , "Getting to the bottom of it" .)