Security is raised in warehouse (7)
I believe the answer is:
deposit
'security' is the definition.
(deposit is a kind of security)
'is raised in warehouse' is the wordplay.
'raised' says the letters should be written backwards.
'in' means one lot of letters goes inside another.
'warehouse' becomes 'depot' (I've seen this before).
'is' written backwards gives 'si'.
'si' placed inside 'depot' is 'DEPOSIT'.
(Other definitions for deposit that I've seen before include "Hoard" , "Down-payment" , "Down payment made to secure goods" , "Returnable sum" , "(Money) laid down" .)