in·flu·ence / ˈinfloŏəns/ • n. the capacity to have an effect on the character, development, or behavior of someone or something, or the effect itself: the influence of television violence I was still under the influence of my parents | their friends are having a bad influence on them. ∎  the power to shape policy or ensure favorable treatment from someone, esp. through status, contacts, or wealth: the institute has considerable influence with teachers. ∎  a person or thing with such a capacity or power: Frank was a good influence on her. ∎  archaic Physics electrical or magnetic induction.• v. [tr.] have an influence on: social forces influencing criminal behavior.PHRASES: under the influence inf. affected by alcoholic drink; drunk: he was charged with driving under the influence.DERIVATIVES: in·flu·ence·a·ble adj.in·flu·enc·er n.ORIGIN: late Middle English: from Old French, or from medieval Latin influentia ‘inflow,’ from Latin influere, from in- ‘into’ + fluere ‘to flow.’ The word originally had the general sense ‘an influx, flowing matter,’ also specifically (in astrology) ‘the flowing in of ethereal fluid (affecting human destiny).’ The sense ‘imperceptible or indirect action exerted to cause changes’ was established in Scholastic Latin by the 13th cent., but not recorded in English until the late 16th cent.

influence (astrol.) emanation of ethereal fluid from the heavens affecting mankind XIV; †infusion of power; †influx XV; insensible action of one on another XVI; power of ascendancy over. — (O)F. influence or medL. influentia (whence also It. influenza), f. prp. of L. influere flow in, f. IN-1 + fluere flow; see -ENCE.
Hence vb. XVII. So influential XVI. f. medL. influentia.

influence In regression analysis, the effect on estimates of parameters of varying the value of a particular observation. Observations that have greatest influence are also called leverage points. Influence functions help to warn of possible over-reliance on too few data values, and also provide a method of allocating new data observations most effectively.

Influence

In mediumistic terminology influence is equivalent to "spirit." The American medium Lenora Piper applied it to objects that, by virtue of association of ideas or magnetism of the late owner, helped her to establish communication with the deceased. The presence of such objects, she declared, helped her to clear the ideas of the communicators. The term influence was used earlier by practitioners of animal magnetism to denote the mesmeric force between operator and subject.