Mosaic pieces (8)
I believe the answer is:
tesserae
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">mosaic pieces</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 tesserae that I've seen before include "Tiles" , "various bits of the picture" , "Mosaic pieces" , "Passwords" .)