Way to completely defeat English (5)
I believe the answer is:
route
'way' is the definition.
(I've seen this before)
'completely defeat english' is the wordplay.
'completely defeat' becomes 'rout' (I've seen this before).
'english' becomes 'e' (abbreviation).
'rout'+'e'='ROUTE'
'to' acts as a link.
(Other definitions for route that I've seen before include "Course, road" , "Course of 7" , "Way travelled" , "track" , "Way, path" .)