Excellent rescue dog minus tail in cricket club (7)
I believe the answer is:
classic
'excellent' is the definition.
(thesaurus)
'tail in cricket club' is the wordplay.
'tail' becomes 'lassi' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'in' is an insertion indicator.
'cricket club' becomes 'cc' (cricketing abbreviation).
'lassi' placed within 'cc' is 'CLASSIC'.
'rescue dog minus' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for classic that I've seen before include "Quintessential" , "Very great work of art" , "Derby, say" , "Artistic work of lasting excellence" , "Good example of its kind" .)