(ækt)  [f. L. act- ppl. stem of ag-re to drive, carry on, do. Probably influenced in its development by ACT n. More than a century intervened between the use of the word by the Sc. poet Henryson, and its first appearance in Eng.] 

    1. trans. To put in motion, move to action, impel; to actuate, influence, animate. Obs.
 
  1602 WARNER Alb. Eng. XIII. lxxvii. 316 Thy Senses fiue that acte thy life; thy Speache, whereby to many Thou doest communicate thy selfe, saue God disclameth any. 1605 TIMME Quersitanus ii. 8 All spirit..in the world is acted & gouerned by the spirit. 1642 ROGERS Naaman 453 There was a different principle that acted them. 1649 H. GUTHRY Mem. (1702) 54 The People of Scotland are much acted by their Ministers Doctrine. 1675 BARCLAY Apol. Quakers II. §1. 19 They are not acted nor led by God's Spirit. 1677 GALE Crt. of Gentiles II. IV. 235 Al his companions, who are acted by the same atheistic principes. 1691 PETTY Pol. Arith. iii. 54 Ships, and Guns do not fight of themselves, but Men who act and manage them. 1712 ADDISON Spec. No. 287 1 If I shall be told that I am acted by prejudice, I am sure it is an honest prejudice. 1732 POPE Ess. on Man ii. 59 Self-love, the spring of motion, acts the soul. 1748 RICHARDSON Clarissa (1811) III. 309 Mrs. Howe was acted by the springs I set at work.
 

    2. To bring into action, bring about, produce, perform, work, make, do (a thing or process). Obs.
 
  1594 GREENE Orl. Furioso 17 Thus did I act as many brave attempts. 1611 SPEED Hist. Gt. Brit. VII. xliv. (1632) 414 Dunstan..who not onely did refuse to act his Coronation. 1649 SELDEN Laws of Eng. II. viii. (1739) 52 Whereby they did get power to act other enormities mentioned in the Charge. 1660 T. STANLEY Hist. Philos. (1701) 82/2, I do most act the business of the Commonwealth, if I practise it only. 1726 DE FOE Hist. Devil I. xi. (1840) 172 Had Satan been able to have acted anything by force. 1791 T. PAINE Rights of Man (ed. 4) 144 Measures which at other times it would censure, it now approves, and acts persuasion upon itself to suffocate its judgment.
 

    3. To carry out in action, work out, perform (a project, command, purpose). arch.
 
  1610 SHAKES. Temp. I. ii. 273 To act her earthy, and abhord commands. 1659 REYNOLDS in Burton Diary (1828) IV. 302 Our enemies..take an advantage of a parliament sitting to act all their plots. 1693 Mem. Count Teckely Pref. 11, A formed Design, intended to be acted in one Place after another, throughout Europe. 1718 POPE Iliad I. 426 The unwilling heralds act their lord's commands. a1842 TENNYSON none 146 To live by law, Acting the law we live by without fear.
 

    4. To carry out or represent in mimic action (an ideal, incident, or story); to perform (a play). Hence fig. in a bad sense: To simulate, counterfeit.
 
  1594 M. DRAYTON in Shaks. Cent. of Praise 13 Acting her passions on our stately stage. 1601 Returne fr. Parnass., Ibid. 48 Let me see you act a little of it. 1602 SHAKES. Ham. II. ii. 455 It was neuer acted: or if it was, not aboue once, for the Play I remember pleas'd not the Million. 1812 J. & H. SMITH Rejec. Addr. v. (1873) 40 It is built to act English plays in. 1823 LAMB Elia Ser. I. xx. (1865) 149 A present sense of the blessing, which can be but feebly acted by the rich. 1849 MACAULAY Hist. Eng. II. 474 Sunderland acted calumniated virtue to perfection. 1858 DICKENS Lett. (1880) II. 43 It is extremely well acted by all concerned.
 

    5. With various complemental phrases, esp. to act out; now spec. in Psychiatry, to represent (one's unconscious impulses, desires, etc.) in action; also absol. or intr., esp. to misbehave, to behave anti-socially (orig. U.S.). Cf. ACTING vbl. n. 3c.
 
  1611 W. GODDARD Sat. Dial. Eb, Oh, her that well cann acte-out such sweete partes. 1646 SIR T. BROWNE Pseud. Ep. I. vi. 23 To act the Fable into a reality. 1659 SOUTH Serm. Matt. x. 33 I. 83 It has been still preached up, but acted down. 1715 BURNET Hist. Own Time II. 237 Lord Tweedale saw, that..he would act over his former extravagances. 1790 BURKE Fr. Rev. Wks. V. 36 This would be to act over again the scene of the criminals condemned to the gallies. 1840 CARLYLE Heroes vi. (1858) 354 To speak-out, to act-out what Nature has laid in him. 1860 E. G. WHITE Spiritual Gifts II. 45 Said Bro. H., ‘If I was well I should partake of this food, and I believe GOD has healed me, and shall act out my faith.’ 1913 Dialect Notes IV. 3 Act out, to misbehave, of children in school, etc. Orono [Maine]. 1934 A. TATE in New Republic 14 Mar. 128/1 The characters..suffer no dramatic alteration; an episode ends when they have acted out enough of the moral to please the poet. 1945 [see ACTING vbl. n. 3c]. 1949 M. MEAD Male & Female ix. 197 Some societies permit periods of licence in which those who feel that they are able to cope with more members of the other sex than are normally permitted to them have a chance to act out their day-dreams without disrupting the social order. 1951 G. HUMPHREY Thinking 310 While a human being thinks his problem out, an animal acts it out. 1965 G. MCINNES Road to Gundagai xi. 192 He persuaded the boys to act out episodes from the Odyssey and the Aeneid. 1974 H. L. FOSTER Ribbin' ii. 46 The child with a learning or physical problem or disability may act-out to divert attention from, for example, his inability to read. 1983 N. HUMPHREY Consciousness Regained vii. 75 Human ancestors were acting out the physiological states of fear or jealousy long before they were in a position to have insight into them.
 

    6. to act a part, or the part of: orig. To sustain the part of one of the characters in a play, hence to simulate. fig. To fulfil the character or duties of.
 
  1611 SHAKES. Cymb. III. iv. 26 That part, thou (Pisanio) must acte for me. 1684 T. BURNET Theo. Earth 185 Our life now is so short..by that time we begin to understand our selves a little, and to know where we are, and how to act our part, we must leave the stage, and give place to others. 1769 Junius Lett. xxxv. 167 You have still an honourable part to act. 1794 PALEY Evid. II. ix. (1817) 211 Those who had acted and were acting the chief parts in the transaction. 1876 FREEMAN Norm. Conq. III. xii. 121 He acted something like the part of a deserter.
 

    7. To act (anyone): To personate, assume the character of, to play; orig. on the stage; fig. in real life; dial. it passes into the sense of mimicking, mocking.
 
  1651 HOBBES Leviathan I. xvi. 80 He that acteth another, is said to beare his Person, or act in his name. 1670 COTTON Espernon III. IX. 470 Why should I take that ill from you, which I suffer from Marais, who every day acts me in your presence? This Marais was..a Buffoon, that had a marvellous faculty of imitation. 1727 SWIFT To Yng. Lady Wks. 1755 II. II. 41 A wise man..soon grows weary of acting the lover and treating his wife like a mistress. 1742 YOUNG Night Th. IV. 556 She gives the soul a soul that acts a god. 1796 GOUV. MORRIS Sparks' Life & Writ. (1832) III. 98 It is to act, not to be, the monarch, and he suits better the theatre than the throne. 1837 J. H. NEWMAN Par. Serm. xxvi. (ed. 3) I. 390 What was it but to act the child, to ask how many times a fellow-Christian should offend against us.
 

    8. a. intr. (object suppressed). To perform on the stage.
 
  1598 J. MARSTON in Shaks. Cent. of Praise 27 Say who acts best? Drusus or Roscio? 1611 CORYAT Crudities 247, I saw women acte, a thing that I neuer saw before, though I haue heard that it hath beene sometimes used in London. a1625 FLETCHER Mad Lover II. i. 8 Plague act yee, I'le act no more. 1718 LADY M. W. MONTAGUE Lett. I. xxi. 64 No women are suffered to act on the stage.
 

    b. Of a play: to be susceptible of being performed (well or otherwise).
 
  1668, 1789 [see READ v. 18a, b]. 1821 BYRON in E. J. Trelawny Rec. Shelley (1858) 29 My plays won't act..my poesy won't sell. 1916 S. KAYE-SMITH John Galsworthy 17 Galsworthy's plays have the advantage of acting wellunlike much literary drama.
 

    9. To perform on the stage of existence; to perform actions, to do things, in the widest sense.    a. With special reference to the reality of the doing, as opposed to think, speak, etc.    b. With reference to the manner or mode of action, and hence = behave, comport, or demean oneself.
 
  1684 Scanderbeg Rediv. vi. 133 The Emperour obliged himself to Act with an Army of Sixty Thousand Men against the Turks. 1742 YOUNG Night Th. II. 92 Who does the best his circumstance allows Does well, acts nobly; angels could no more. 1751 JORTIN Serm. (1771) VII. i. 13 Who beleeve in Christ, with a resolution to act suitably to this persuasion. 1756 BURKE Vind. Nat. Soc. Wks. I. 14 We begin to think and to act from reason and from nature alone. 1833 H. MARTINEAU Loom & Lug. I. iv. 54, I never could act for myself in my life. 1846 SIR R. PEEL Sp. on resigning 28 June, Acting..from pure and disinterested motives. 1865 MILL Repr. Gov. 8/2 It is what men think, that determines how they act. 1876 FREEMAN Norm. Conq. IV. xviii. 145 In overcoming the hostility of the West, William acted as he always did act.
 

    c. To do the duties of an office temporarily, without being the regular officer; to act for, or in the absence of another. To act as: To perform in the character of, to do the work of, to serve as. (Also of things.)
 
  1804 [See under ACTING vbl. n. 5a.] 1849 MACAULAY Hist. Eng. I. 490 He had no scruple about acting as chaplain. 1857 LIVINGSTONE Trav. vi. 114 A person who acted as interpreter. 1879 G. C. HARLAN Eyesight ii. 25 They [the eye-lashes] are delicately sensitive to the slightest touch, and act as feelers to warn the eye of the approach of any small object. Mod. Is any one empowered to act in the manager's absence? Mod. I am here to act for my brother; to act in behalf of the children.
 

    d. To act on, upon: To regulate one's conduct according to.
 
  1814 JANE AUSTEN Mansf. Park III. x. 201 It was somehow or other ascertained, or inferred, or at least acted upon, that they were not at all afraid. 1847 TENNYSON Princess II. 211 If more there be, If more and acted on, what follows? Mod. I wish the maxim were more generally acted upon in all cases.
 

    e. To act up to: To come up in practice to an assumed standard, to fulfil or carry out in practice.
 
  1747 in Col. Rec. Penn. V. 149 As long as you shall act up to your Engagements. 1829 LANDOR Imag. Convers. (1842) II. 99 Your lordship acts up to your tenets. 1849 MACAULAY Hist. Eng. II. 63 That..the members of the Church of England would act up to their principles.
 

    f. to act up: to act in an abnormal or unexpected manner; to ‘put on an act’; to become unruly, to ‘play up’. colloq.
 
  1903 A. ADAMS Log Cowboy xviii. 275 The horse of some peeler..acted up one morning. 1929 D. H. LAWRENCE My Skirmish with Jolly Roger 8 When people act in sex, nowadays they are half the time acting up. 1956 J. HEARNE Stranger at Gate xxxvii. 282 ‘I'm sorry,’ he said, ‘I'm acting up a bit. I feel pretty tight inside.’ 1964 New Statesman 20 Nov. 786/2 She would have to ‘act up’ to convince anyone that her mental health is in danger.
 

    10. a. Of things: To put forth energy, produce effects, exert influence, fulfil functions.
 
  1751 JOHNSON Rambler No. 141 2, A combination of inconsiderable circumstances, acting when his imagination was unoccupied. 1812 W. TAYLOR in Month. Rev. LXIX. 384 Rapid composition acts best. 1870 JEVONS Elem. Logic xxix. 251 When several causes act at once. 1878 HUXLEY Physiogr. 63 A fall of snow thus acts like a mantle of fur thrown over the earth. Mod. The brake refused to act.
 

    b. To act on: To exert influence on; to influence, affect. (Here act on comes round nearly to the earliest transitive sense of act; see 1.)
 
  1810 COLERIDGE Friend (1865) 124 Reason to act on man must be impersonated. 1812 SIR H. DAVY Chem. Philos. 437 The clear liquor..is acted on by a rod of zinc. 1855 BREWSTER Life of Newton I. xii. 322 One sphere will act upon another with a force directly proportional to their quantities of matter. 1855 BAIN Senses & Intell. II. ii. §2 (1864) 177 Gases do not act on the touch.