Obscure English knight against European from the East (7)
I believe the answer is:
envelop
'obscure' is the definition.
(I've seen this before)
'english knight against european from the east' is the wordplay.
'english' becomes 'e' (abbreviation).
'knight' becomes 'N' (abbreviation for knight in chess).
'against' becomes 'v' (abbreviation for 'versus').
'european' becomes 'pole' (Pole is an example).
'from the east' says the letters should be written in reverse.
'pole' written backwards gives 'elop'.
'e'+'n'+'v'+'elop'='ENVELOP'
(Other definitions for envelop that I've seen before include "Surround and embrace" , "Cover completely" , "Ring" , "Wrap up - pen love (anag)" , "Shroud, cover up" .)