1. A power affecting a person, thing, or course of events, especially one that operates without any direct or apparent effort: the pervasive influence that TV has on modern life; young people falling under the influence of a radical philosopher.
2. Power to sway or affect based on prestige, wealth, ability, or position: used her family's influence to get the job.
3. A person who exerts such power: My parents considered my friend to be a bad influence on me.
a. A determining factor believed by some to affect individual tendencies and characteristics understood to be caused by the positions of the stars and planets at the time of one's birth.
b. Factors believed to be caused by the changing positions of the stars and planets in relation to their positions at the time of one's birth.
tr.v. in·flu·enced, in·flu·enc·ing, in·flu·enc·esIdiom:
1. To have an influence on (something); change: a news report that influenced the outcome of the election.
2. To change the behavior or thinking of (someone); sway: negative ads that are intended to influence voters.
under the influence
Intoxicated, especially with alcohol.
[Middle English, from Old French, from Medieval Latin īnfluentia, influx, from Latin īnfluēns, īnfluent-, present participle of īnfluere, to flow in : in-, in; see IN-2 + fluere, to flow; see bhleu- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.