Pickled cucumber (7)
I believe the answer is:
gherkin
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pickled cucumber</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 gherkin that I've seen before include "Salad vegetable - City of London skyscraper" , "Small cucumber pickled whole" , "Type of small cucumber" , "Small cucumber, usually pickled" , "Harmony" .)