1. impingement(n = noun.act) encroachment, impact - influencing strongly; "they resented the impingement of American values on European culture"
is a kind of influence
Derived form verb impinge1
2. impingement(n = noun.act) impaction - a sharp collision produced by striking or dashing against something;
is a kind of crash, smash
The act of impinging. [1913 Webster]