A glass container (6)
I believe the answer is:
bottle
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">a glass container</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for bottle that I've seen before include "Grit" , "confidence" , "Heart" , "See 11" , "intrepidity?" .)