Use English tactic to trap millions (6)
I believe the answer is:
employ
'use' is the definition.
(synonyms)
'english tactic to trap millions' is the wordplay.
'english' becomes 'E' (abbreviation).
'tactic' becomes 'ploy' (I've seen this in other clues).
'to trap' means one lot of letters goes inside another.
'millions' becomes 'm' (abbreviation).
'e'+'ploy'='eploy'
'eploy' placed around 'm' is 'EMPLOY'.
(Other definitions for employ that I've seen before include "Keep (someone) occupied" , "occupation" , "Put on the payroll" , "Take into service" , "Use or give job to" .)