Jam container (3)
I believe the answer is:
jar
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">jam container</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for jar that I've seen before include "Glass of beer; clash" , "Container; be incongruous" , "(Jam) pot" , "Grate" , "Jolt with glass container" .)