1.Definition: a forceful consequence; a strong effect

"The book had an important impact on my thinking", "The book packs a wallop"

Related Noun(s):wallop

Category: General

2.Definition: influencing strongly

Related Noun(s):encroachment

Category: General

3.Definition: the striking of one body against another

Category: General

4.Definition: the violent interaction of individuals or groups entering into combat

Related Noun(s):shock

Category: General