Noun

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.

* {{quote-magazine, date=2013-07-26, author=(Leo Hickman)

, volume=189, issue=7, page=26, magazine=(The Guardian Weekly) , title= How algorithms rule the world , passage=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.}}

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

A person or thing exerting such power or action.

* {{quote-magazine, year=2013, month=May-June, author= Katrina G. Claw

, title= Rapid Evolution in Eggs and Sperm , volume=101, issue=3, magazine=(American Scientist) , passage=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.}}

(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.

(obsolete) The action of flowing in; influx.

* Hooker

God hath his influence into the very essence of all things.

(electricity) Electrostatic induction.

Noun

(-)

the quality of being useful, to which extent something is useful

The usefulness of his latest reorganisation has been disputed.