Influence is the power to make other people agree with your opinions or do what you want.

If you influence someone, you use your power to make them agree with you or do what you want.

To have an influence on people or situations means to affect what they do or what happens.

If someone or something influences a person or situation, they have an effect on that person's behaviour or that situation.

Someone or something that is a good or bad influence on people has a good or bad effect on them.

If you are under the influence of someone or something, you are being affected or controlled by them.

If someone is under the influence, their mind is affected by alcohol or drugs.