Complicated in structure (7)
I believe the answer is:
complex
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">complicated in structure</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 complex that I've seen before include "with real and imaginary parts" , "Involved" , "Far from simple" , "Not simple, say a group of feelings" , "Obsession - not simple" .)