Implement let us in after manipulation (7)
I believe the answer is:
utensil
'implement' is the definition.
(utensil is a kind of implement)
'let us in after manipulation' is the wordplay.
'after manipulation' indicates anagramming the letters (I've seen this in other clues).
'let'+'us'+'in'='letusin'
'letusin' with letters rearranged gives 'UTENSIL'.
(Other definitions for utensil that I've seen before include "Mandolin, perhaps" , "Can opener, for example" , "Containers for kitchen use" , "A tool for household use" , "Implement for practical use" .)