Stop and lean on an inventory (9)
I believe the answer is:
checklist
'an inventory' is the definition.
(thesaurus)
'stop and lean' is the wordplay.
'stop' becomes 'check' (checking is a kind of stopping).
'and' says to put letters next to each other.
'lean' becomes 'list' (both can mean to tilt).
'check'+'list'='CHECKLIST'
'on' is the link.
(Other definitions for checklist that I've seen before include "What's used to verify" , "Reminder, itemised" , "sort of schedule" , "Items to be performed" .)