One hundred and fifty die outside changing room (7)
I believe the answer is:
cubicle
'changing room' is the definition.
(I've seen this before)
'one hundred and fifty die outside' is the wordplay.
I cannot quite see how this works, but
'one' could be 'i' (Roman numeral) and 'i' is found in the answer.
'hundred' could be 'c' (Roman numeral) and 'c' is located in the answer.
'fifty' could be 'l' (Roman numeral) and 'l' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for cubicle that I've seen before include "Small changing room" , "Small room for special use" , "Booth - kiosk" , "Small partitioned-off area" , "Cell" .)