Strong drinks on the house for mavericks (4,7)
I believe the answer is:
free spirits
'mavericks' is the definition.
(I've seen this before)
'strong drinks on the house' is the wordplay.
I cannot really see how this works, but
'strong' could be 'f' (musical symbol for 'forte', 'strong' in Italian) and 'f' is found within the answer.
'on' could be 're' ('on' can be mean 'with reference to') and 're' is located in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is present in the answer.
This explanation may well be incorrect...
'for' acts as a link.
Can you help me to learn more?
(Another definition for free spirits that I've seen is " Mavericks".)