Crucible girl can put on good snooker shot (7,3)
I believe the answer is:
melting pot
'crucible' is the definition.
(synonyms)
'girl can put on good snooker shot' is the wordplay.
'girl' becomes 'Mel' (short for Melanie).
'can' becomes 'tin' (synonyms).
'put on good' becomes 'g' (I can't justify this - if you can you should give a lot more credence to this answer).
'snooker shot' becomes 'pot' (as in potting a ball in snooker).
'mel'+'tin'+'g'+'pot'='MELTING-POT'
Can you help me to learn more?
(Other definitions for melting pot that I've seen before include "Dissolving container" , "Vessel - place for mixture" , "In which to mix metals, immigrants" , "Crucible'" , "multicultural area" .)