Hard work’s upset a delicate lass (5)
I believe the answer is:
sylph
This clue could be a double definition.
'hard work's upset' is the first definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'a delicate lass' is the second definition.
(sylph can mean a slender young woman)
Can you help me to learn more?
(Other definitions for sylph that I've seen before include "Slender, graceful girl" , "Slim woman" , "Imaginary (female) being" , "Slim person" , "Slender and graceful young woman" .)