Merchandise finally put in place in an Irishman’s warehouse (10)
I believe the answer is:
repository
'warehouse' is the definition.
(a warehouse is a repository of things)
'merchandise finally put in place in an irishman's' is the wordplay.
'finally' suggests the final letters.
'put in place' becomes 'posit' (posit can mean to position something).
'in' is an insertion indicator.
'an irishman' becomes 'Rory' (common Irish name).
The last letter of 'merchandise' is 'e'.
'e'+'posit'='eposit'
'eposit' going inside 'rory' is 'REPOSITORY'.
(Other definitions for repository that I've seen before include "Warehouse" , "cabinet" , "Storage place" , "Box containing items for safekeeping" , "dump?" .)