150 with nothing put in small room (6)
I believe the answer is:
closet
'small room' is the definition.
(I've seen this before)
'150 with nothing put' is the wordplay.
'150' becomes 'cl'.
'with nothing' becomes 'o' (I've seen this in other clues).
'put' becomes 'set' (setting is a kind of putting).
'cl'+'o'+'set'='CLOSET'
'in' is the link.
(Other definitions for closet that I've seen before include "Compartment for clothing in the US" , "Study" , "Small room or wardrobe" , "A small room or cupboard" , "Furtive" .)