Superficial, lacking depth (7)
I believe the answer is:
shallow
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">superficial</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >'<span class="explanation-format__original">lacking depth</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for shallow that I've seen before include "flimsy" , "Without depth" , "Trivial" , "Of water, not deep" , "Superficial" .)