Paper bags I install (3)
I believe the answer is:
fit
'install' is the definition.
(thesaurus)
'paper bags i' is the wordplay.
'paper' becomes 'ft' (Financial Times newspaper).
'bags' is an insertion indicator (bag can mean secures or steals).
'ft' enclosing 'i' is 'FIT'.
(Other definitions for fit that I've seen before include "Suit" , "Adapt; well" , "Paroxysm" , "Appropriate -- not 21" , "Certified OK by the doctor" .)