Pickled cucumber (7)
I believe the answer is:
gherkin
'pickled cucumber' is the definition.
(I've seen this before)
This is all the clue.
(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" .)