Letter holder (8)
I believe the answer is:
envelope
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">letter holder</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 envelope that I've seen before include "Container for letter" , "note might be put into this" , "Item of mail" , "what's to be posted in here?" , "Paper wrapper" .)