from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun The process of doing or performing something.
  • noun Something done or performed; a deed.
  • noun Law Something done that has legal significance.
  • noun A statute or other law formally adopted by a legislative body.
  • noun A formal written record of proceedings or transactions.
  • noun One of the major divisions of a play, opera, or film.
  • noun A performance or entertainment usually forming part of a longer presentation.
  • noun The actor or actors presenting such a performance.
  • noun A manifestation of intentional or unintentional insincerity; a pose.
  • intransitive verb To play the part of; assume the dramatic role of.
  • intransitive verb To perform (a role) on the stage.
  • intransitive verb To behave like or pose as; impersonate.
  • intransitive verb To behave in a manner suitable for.
  • intransitive verb To behave or comport oneself.
  • intransitive verb To perform in a dramatic role or roles.
  • intransitive verb To be suitable for theatrical performance.
  • intransitive verb To behave affectedly or unnaturally; pretend.
  • intransitive verb To appear or seem to be.
  • intransitive verb To carry out an action.
  • intransitive verb To operate or function in a specific way.
  • intransitive verb To serve or function as a substitute for another.
  • intransitive verb To produce an effect.
  • idiom (be in on the act) To be included in an activity.
  • idiom (clean up (one's) act) To improve one's behavior or performance.
  • idiom (get into the act) To insert oneself into an ongoing activity, project, or situation.
  • idiom (get (one's) act together) To get organized.

from The Century Dictionary.

  • noun A second act (1890) which provided for an annual appropriation, to be increased in ten years from $15,000 to a permanent sum of $25,000 from the proceeds of the sale of public land, for the more complete endowment of these institutions. This income could be applied only to instruction (with facilities) in agriculture, the mechanic arts, the English language, and other branches directly related to industrial life.
  • To do, perform, or transact.
  • To represent by action; perform on or as on the stage; play, or play the part of; hence, feign or counterfeit: as, to act Macbeth; to act the lover, or the part of a lover.
  • To perform the office of; assume the character of: as, to act the hero.
  • To put in action; actuate.
  • To do something; exert energy or force in any way: used of anything capable of movement, either original or communicated, or of producing effects. Specifically
  • To put forth effort or energy; exercise movement or agency; be employed or operative: as, to act vigorously or languidly; he is acting against his own interest; his mind acts sluggishly.
  • To exert influence or produce effects: perform a function or functions; operate: as, praise acts as a stimulant; mind acts upon mind; the medicine failed to act; the brake refused to act, or to act upon the wheels.
  • To be employed or operate in a particular way; perform specific duties or functions: as, a deputy acts for or in place of his principal; he refused to act on or as a member of the committee.
  • To perform as an actor; represent a character; hence, to feign or assume a part: as, he acts well; he is only acting.
  • He is a man of sentiment, and acts up to the sentiments he professes. Sheridan, School for Scandal, i. 2. Synonyms Act, Work, Operate. These words agree in expressing the successful exertion of power. In their intransitive use they are sometimes interchangeable: as, a medicine acts, works, or operates; a plan works or operates. Where they differ, act may more often refer to a single action or to the simpler forms of action: as, a machine works well when all its parts act. Act may also be the most general, applying to persons or things, the others applying generally to things. Operate, may express the more elaborate forms of action. Work may express the more powerful kinds of action: as, it worked upon his mind.
  • noun An exertion of energy or force, physical or mental; anything that is done or performed; a doing or deed; an operation or performance.
  • noun A state of real existence, as opposed to a possibility, power, or being in germ merely; actuality; actualization; entelechy.
  • noun The soul, according to the Aristotelians, is the act, that is, is the entelechy or perfect development of the body. So God is said to be pure act, for Aristotle says, “There must be a principle whose essence it is to be actual (η%148ς ἠ ον)σία ἐνε)ργεια),” and this is by many writers understood to mean “whose essence is to be active.” In the phrase in act, therefore, act, though properly meaning actuality, is often used to mean activity.
  • noun A part or division of a play performed consecutively or without a fall of the curtain, in which a definite and coherent portion of the plot is represented: generally subdivided into smaller portions, called scenes.


from The American Heritage® Dictionary of the English Language, 4th Edition

[Middle English, from Old French acte, from Latin āctus, a doing, and āctum, a thing done, both from past participle of agere, to drive, do; see ag- in Indo-European roots.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

Old French acte, from Latin ācta ("register of events"), plural of āctum ("decree, law"), from agō ("put in motion").


Help support Wordnik (and make this page ad-free) by adopting the word act.


  • 'Abortion is a racist, genocidal act' yahooBuzzArticleHeadline = '\'Abortion is a racist, genocidal act\' '; yahooBuzzArticleSummary =' Article: Info on the latest anti-abortion propaganda. '

    'Abortion is a racist, genocidal act'

  • As I consider it one of the most important qualifications in a judge to have the discernment I refer to, and as many are appointed judges, even at our national shows, _who never should have been appointed, and many act who never should act_, it ought to be put out of all doubt.

    Cattle and Cattle-breeders

  • So far as the Scriptures seem to suggest there is not a fresh act upon God's part at certain times in one's experience, but His wondrous love is such that there is _a continuous act_ -- a continuous flooding in of all the gracious power of His Spirit that the human conditions will admit of.

    Quiet Talks on Power

  • Or do we find, when we are engaged in an act of the will, that the mental stream contains only the familiar old elements of attention, perception, judgment, desire, purpose, etc., _all organized or set for the purpose of accomplishing or preventing some act_?

    The Mind and Its Education

  • Absolute -- all this begetting of Divine Children -- was in the nature of a single act rather than as a series of acts, if we may be permitted to speak of the manifestation as an _act_.

    A Series of Lessons in Raja Yoga

  • Yes, if you consider the amusement in the abstract: but if you take it as _this human act_, the act is inordinate and evil in itself, or as it is elicited in the mind of the agent.

    Moral Philosophy

  • My father is very anxious, I think, to act the play; my mother, to have it published before it is acted; and I sit and hear it discussed and praised and criticised, only longing (like a "silly wench," as my mother calls me when I confess as much to her) to see my father in his lovely dress and hear the _alarums of my fifth act_.

    Records of a Girlhood

  • Miss Brown, I'll give in, that you and Mr. Brown _do_ act up to your principles; you certainly _act_ as if you were willing to be damned '; -- and so do all those folks who will live on the blood and groans of the poor Africans, as the Doctor said; and I should think, by the way Newport people are making their money, that they were all pretty willing to go that way, -- though, whether it's for the glory of God, or not, I'm doubting.

    The Atlantic Monthly, Volume 04, No. 21, July, 1859

  • _acting_, His _essence_ being _to act_, for otherwise he might _never_ have acted, and the existence of the world would be an accident; for what should have, in that case, decided Him to act, after long inactivity?

    Morals and Dogma of the Ancient and Accepted Scottish Rite of Freemasonry

  • Wherefore if the mind should prefer a weak inclination to a strong one, _it would act against itself, and otherwise than it is disposed to act_.”

    A Theodicy, or, Vindication of the Divine Glory


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