Checkpoint entirely controlling import (6)
I believe the answer is:
intent
'import' is the definition.
(intent is a kind of import)
'checkpoint entirely controlling' is the wordplay.
'controlling' indicates the answer is hidden within the clue (the solution is controlled or contained).
'INTENT' can be found hidden inside 'checkpoint entirely'.
(Other definitions for intent that I've seen before include "Purpose; determined" , "Earnest, purpose" , "Bent on, determined to" , "Focused" , "Bent on, resolved" .)