Alien in favour of grabbing control over English (9)
I believe the answer is:
foreigner
'alien' is the definition.
(foreigner is a kind of alien)
'in favour of grabbing control over english' is the wordplay.
'in favour of' becomes 'for' (I've seen this before).
'grabbing' means one lot of letters goes inside another.
'control' becomes 'reign' (reign is a kind of control**).
'over' means one lot of letters go next to another.
'english' becomes 'e' (abbreviation).
'reign'+'e'='reigne'
'for' going around 'reigne' is 'FOREIGNER'.
(Other definitions for foreigner that I've seen before include "chauvinist holds in contempt" , "Stranger, outsider" , "asylum seeker?" , "One from abroad" , "Alien" .)