The noun is pronounced /ɪmpækt/. The verb is pronounced /ɪmpækt/.
( impacted)
Frequency: The word is one of the 1500 most common words in English.
1.
The impact that something has on a situation, process, or person is a sudden and powerful effect that it has on them.
They say they expect the meeting to have a marked impact on the future of the country...
When an executive comes into a new job, he wants to quickly make an impact.
N-COUNT : usu sing , oft N on n
2.
An impact is the action of one object hitting another, or the force with which one object hits another.
The plane is destroyed, a complete wreck: the pilot must have died on impact...
N-VAR
3.
To impact on a situation, process, or person means to affect them.
Such schemes mean little unless they impact on people.
...the potential for women to impact the political process.
VERB : V on/upon n , V n
4.
If one object impacts on another, it hits it with great force. ( FORMAL )
...the sharp tinkle of metal impacting on stone...
When a large object impacts the Earth, it makes a crater.
VERB : V on/upon/with n , V n