influence

Etymology

From Middle English influence, from Old French influence (“emanation from the stars affecting one's fate”), from Medieval Latin īnfluentia, from Latin īnfluēns (“flowing in”), present active participle of īnfluō (“flow into”), from in- (“in-”) + fluō (“flow”). Doublet of influenza.

noun

1. 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.
   The use of algorithms in policing is one example of their increasing influence on our lives. And, as their ubiquity spreads, so too does the debate around whether we should allow ourselves to become so reliant on them – and who, if anyone, is policing their use. 2013-07-26, Leo Hickman, “How algorithms rule the world”, in The Guardian Weekly, volume 189, number 7, page 26
2. 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.
   Terra Firma is an Alliance political party formed after the First Contact War. Its policy agenda is based on the principle that Earth must 'stand firm' against alien influences. This covers a variety of legislation. Recent activities by Terra Firma include opposition to a law requiring high school alien language study, a proposal to increase tariffs on alien imports, and leading a popular movement to mark the First Contact War with a public holiday. 2008, BioWare, Mass Effect, Redwood City: Electronic Arts, →OCLC, PC, scene: Terra Firma Party Codex entry
3. A person or thing exerting such power or action.
   He has been a great influence on the voters during the elections.
   Many genes with reproductive roles also have antibacterial and immune functions, which indicate that the threat of microbial attack on the sperm or egg may be a major influence on rapid evolution during reproduction. 2013 May-June, Katrina G. Claw, “Rapid Evolution in Eggs and Sperm”, in American Scientist, volume 101, number 3
4. (astrology) An element believed to determine someone's character or individual tendencies, caused by the position of the stars and planets at the time of one's birth.
5. (obsolete) The action of flowing in; influx.
6. (electricity) Electrostatic induction.

verb

1. (transitive) 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.
   The politician wants to influence the public.
   I must admit that this book influenced my outlook on life.
2. (intransitive) To exert, make use of one's influence.
3. (transitive, obsolete) To cause to flow in or into; infuse; instill.