Obscure European Community borders with Spain (7)
I believe the answer is:
Here is my best explanation:
'obscure' is the definition.
(eclipsing is a kind of obscuring)
'european community borders with spain' is the subsidiary indication.
'european community' becomes 'ec'.
'borders' becomes 'lips'.
'with' means one lot of letters go next to another.
'spain' becomes 'e' (abbreviation for Espana).
(Other definitions for eclipse that I've seen before include "Lunar/solar phenomenon", "Surpass, outshine", "Cut out", "Celestial obscuration of light", "Solar phenomenon", "Throw into obscurity, outshine", "Obscure light from (other celestial body)", "Obscurement of one heavenly body by another", "Blocking of light" and "The blocking of light of one heavenly body by another".)