Interlock(ing) (4)
I believe the answer is:
mesh
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">interlocking</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for mesh that I've seen before include "Interconnected configuration" , "Grid, netting" , "Lattice" , "Interlaced structure" , "Netting made of wire or thread" .)