lacking experience (5)
I believe the answer is:
naive
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">lacking experience</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 naive that I've seen before include "Too credulous or trusting" , "Rather too simple and ingenuous" , "Too simple and trusting" , "Lacking wisdom and judgement" , "Unaffected; credulous" .)