A driven out intruder (7)
I believe the answer is:
invader
'intruder' is the definition.
(invader is a kind of intruder)
'a driven out' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'a'+'driven'='adriven'
'adriven' is an anagram of 'INVADER'.
(Other definitions for invader that I've seen before include "Attacker from abroad" , "One entering as an enemy" , "One illegally entering" , "Attacker from outside" , "One enters by force to conquer" .)