Encroach, impinge (8)
I believe the answer is:
infringe
I believe this clue is a double definition.
'encroach' is the first definition.
(I know that encroach can be written as infringe)
'impinge' is the second definition.
(I know that impinge can be written as infringe)
(Other definitions for infringe that I've seen before include "Break (rule)" , "Encroach, impinge" , "Violate" , "Break the rules" , "Contravene" .)