Dwarf prunes planted in eastern Spain (7)
I believe the answer is:
eclipse
'dwarf' is the definition.
(I've seen this in another clue)
'prunes planted in eastern spain' is the wordplay.
'prunes' becomes 'clips' ('clip' can be a synonym of 'prune').
'planted in' means one lot of letters goes inside another.
'eastern' becomes 'e'.
'spain' becomes 'e' (abbreviation for Espana).
'e'+'e'='ee'
'clips' placed into 'ee' is 'ECLIPSE'.
(Other definitions for eclipse that I've seen before include "Ennui" , "Lunar or solar phenomenon" , "Heavenly event; drake's time of dull plumage" , "When one celestial body obscures another" , "Block" .)