Generous admission of liability stops arrests (7)
I believe the answer is:
copious
'generous' is the definition.
(thesaurus)
'admission of liability stops arrests' is the wordplay.
'admission of liability' becomes 'IOU' (I owe you, a promise to pay a debt).
'stops' is an insertion indicator.
'arrests' becomes 'cops' ('cop' can be a synonym of 'arrest').
'iou' inserted inside 'cops' is 'COPIOUS'.
(Other definitions for copious that I've seen before include "Ample" , "great supply?" , "Abundant in quantity" , "Providing loads of" , "Rich" .)