Small cucumber (7)
I believe the answer is:
gherkin
'small cucumber' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for gherkin that I've seen before include "Pickled item" , "Small cucumber pickled whole" , "Salad vegetable - City of London skyscraper" , "Type of small cucumber" , "Variety of small cucumber" .)