Small oval citrus fruit (7)
I believe the answer is:
kumquat
'small oval citrus fruit' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for kumquat that I've seen before include "Asian citrus-like fruit" , "Small oval citrus fruit" , "Chinese orange fruit" , "Small orange fruit" , "Small orange-like fruit" .)