The power to affect, control or manipulate something or someone; the ability to change the development of fluctuating things such as conduct, thoughts or decisions.

“I have absolutely no influence over him.”

An action exerted by a person or thing with such power on another to cause change.

“I'm not able to exercise influence over him.”

A person or thing exerting such power or action.

“He has been a great influence on the voters during the elections.”

To have an effect on by using gentle or subtle action; to exert an influence upon; to modify, bias, or sway; to persuade or induce.

“I must admit that this book influenced my outlook on life.”

To exert, make use of one's influence.

To cause to flow in or into; infuse; instill.