Chest, box (5)
I believe the answer is:
crate
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">chest</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >'<span class="explanation-format__original">box</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that crate is a type of box)</span><br/ ><br/ ></span>
(Other definitions for crate that I've seen before include "Box for shipping" , "Dilapidated vehicle" , "Packing-case made of wooden slats" , "Packing container" , "heap" .)