English naval officer is about to impress (10)
I believe the answer is:
commandeer
'impress' is the definition.
(thesaurus)
'english naval officer is about' is the wordplay.
'english' becomes 'e' (abbreviation).
'naval officer' becomes 'commander' (I've seen this before).
'is about' indicates putting letters inside.
'e' placed into 'commander' is 'COMMANDEER'.
'to' acts as a link.
(Other definitions for commandeer that I've seen before include "Take by force" , "requisition" , "Seize" , "Confiscate" , "Appropriate" .)