Good when the glass is going up (6)
I believe the answer is:
health
'good' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for health that I've seen before include "State of well-being" , "Fettle -- condition" , "Freedom from illness" , "Fit condition" , "It's said to be more than wealth" .)