Thin sheet one reveals, the end cut (6,7)
I believe the answer is:
'thin sheet' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'one reveals the end cut' is the wordplay.
'one reveals' becomes 'shower' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'the end' becomes 'curtains' ('curtains' can mean someone's end or demise).
'cut' means to remove the last letter.
'curtains' with its final letter removed is 'curtain'.
Can you help me to learn more?
(Other definitions for shower curtain that I've seen before include "Splash preventer" , "Bathroom protector" , "Bathroom screen?" , "Bathroom hang-up?" , "Bathroom barrier" .)