noun
definition:
The impact of something is its effect or influence. If a movie has a strong impact on you, it does something to you. It makes you feel something strongly or it makes you think very much.
example:
My dad said that his high school chemistry teacher had a strong impact on him. Because of this teacher, my dad learned to love chemistry. That’s why he became a teacher of chemistry himself.
See the full entry in Wordsmyth Elementary Children’s Dictionary