Precious little stone (3)
I believe the answer is:
gem
This might be a double definition.
'precious little' is the first definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'stone' is the second definition.
(a gemstone)
Can you help me to learn more?
(Other definitions for gem that I've seen before include "Pleasant and cheerful (from German)" , "A jewel of an Orangeman" , "Pearl" , "Setter might bed this" , "Valued person; jewel" .)