At which cosmetics are assessed? (4,5)
I believe the answer is:
face value
'at which cosmetics are assessed?' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
This is all the clue.
Can you help me to learn more?
(Other definitions for face value that I've seen before include "what it's apparently worth" , "really not worth it?" , "Apparent worth" , "not an excessive price" , "Amount as printed or stamped on money or other object" .)