To let Blair loose without constraints, they must accept it (7)
I believe the answer is:
hirable
'must accept it' is the definition.
I can't tell whether this definition defines the answer.
'to let blair loose without constraints they' is the wordplay.
I cannot really see how this works, but
an anagram of 'blair' is 'irabl' which is located in the answer.
The remaining letters 'he' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for hirable that I've seen is " can be rented".)