<B>act, </B>noun, verb.<DL COMPACT><DD><I>noun </I> <B>1. </B>something done; a doing or performance; a deed. <BR> <I>Ex. an act of kindness. Slapping his face was a childish act.</I> <DD><B> 2. </B>process of doing; action. <BR> <I>Ex. The farmer caught the boys in the act of stealing his apples.</I> <DD><B> 3a. </B>one of the main divisions of a play or opera. <BR> <I>Ex. Most modern plays have three acts.</I> <DD><B> b. </B>one of several short performances on a program, such as a variety or television show. <BR> <I>Ex. We stayed to see the trained dog's act.</I> <DD><B> 4. </B>the decision of a legislature; law; statute. An act of Congress is a bill that has been passed by Congress. (SYN) decree. <DD><B> 5. </B>(Informal, Figurative.) a display of affected or pretended behavior. <BR> <I>Ex. She's not angry; she's just putting on an act.</I> <DD><I>v.i. </I> <B>1. </B>to do something. <BR> <I>Ex. At the alarm, the firemen acted promptly and saved the burning house. Act, act in the living present (Longfellow).</I> <DD><B> 2. </B>to have effect. <BR> <I>Ex. The medicine acted like magic.</I> <DD><B> 3. </B>to behave. <BR> <I>Ex. The boy acted badly in school. She acts as if she were tired.</I> <DD><B> 4a. </B>to perform on the stage, in motion pictures, on television, or over the radio; play a part. <BR> <I>Ex. He acts very well.</I> <DD><B> b. </B>(of a play or role) to be capable of being performed. <DD><B> 5. </B>(Figurative.) to pretend. <BR> <I>Ex. Her anger is not genuine; she is acting.</I> (SYN) feign. <DD><I>v.t. </I> <B>1. </B>to behave like. <BR> <I>Ex. Most people act the fool now and then.</I> <DD><B> 2. </B>(Figurative.) to perform or play the part of (a character) on the stage, in motion pictures, on television, or over the radio; play (a role). <BR> <I>Ex. to act Macbeth. The handsome man acts the part of the hero.</I> (SYN) enact. <DD><B> 3. </B>(Obsolete.) to animate. <BR><I>expr. <B>act as,</B> </I>to carry out the functions of. <BR> <I>Ex. to act as chaplain.</I> <BR><I>expr. <B>act for,</B> </I>to take the place of; do the work of; act in behalf of. <BR> <I>Ex. While the principal was gone, the assistant principal acted for him.</I> <BR><I>expr. <B>act on,</B> <DD><B> a. </B>to follow; obey. </I> <I>Ex. to act on the principle of the golden rule. I will act on your suggestion.</I> <DD><B> b. </B>to have an effect or influence on. <BR> <I>Ex. Yeast acts on dough and makes it rise.</I> <BR><I>expr. <B>act out,</B> <DD><B> a. </B>to portray as an actor. </I> <I>Ex. to act out the heroine's part in detail.</I> <DD><B> b. </B>to express (unconscious or repressed feelings, fantasies, or frustrations) by one's actions or behavior. <BR> <I>Ex. To observe that children act out the secret wishes of their parents is true enough parlor psychology (New York Times).</I> <BR><I>expr. <B>act up,</B> (Informal.) <DD><B> a. </B>to behave badly. </I> <I>Ex. The spoiled girl acted up whenever company came.</I> <DD><B> b. </B>to play tricks; make mischief. <BR> <I>Ex. Children often act up on Halloween. [The] five-year-old had been acting up ... and driving her father up the wall (Maclean's).</I> <BR><I>expr. <B>act upon,</B> <DD><B> a. </B>to be influenced by and follow. </I> <I>Ex. By acting upon his teacher's advice on how to study, he improved his grades considerably.</I> <DD><B> b. </B>to have an effect or influence on. <BR> <I>Ex. One sphere will act upon another with a force directly proportional to their quantities of matter (David Brewster).</I> <BR><I>expr. <B>get into</B> (or <B>in on</B>) <B>the act,</B> </I>(Informal.) to join in or take part in an activity, especially in something expedient or fashionable. <BR> <I>Ex. As soon as Ping-Pong became fashionable everybody stopped snickering and tried to get in on the act.</I> <BR><I>expr. <B>get one's act together,</B> </I>(U.S. Informal.) to get organized; eliminate differences, inconsistencies, and the like. <BR> <I>Ex. There I was, ... weeping, feeling like a miserable, self-indulgent, neurotic, middle-aged woman who couldn't get her act together (Eleanor Coppola).</I> </DL>
<A NAME="acta">
<B>acta, </B>noun pl.<DL COMPACT><DD> acts; deeds; proceedings; records. </DL>
<A NAME="actability">
<B>actability, </B>noun.<DL COMPACT><DD> actable quality or condition. </DL>
<A NAME="actable">
<B>actable, </B>adjective.<DL COMPACT><DD><B> 1. </B>that can be acted (on the stage). <DD><B> 2. </B>that can be done. </DL>
<A NAME="actaeon">
<B>Actaeon, </B>noun.<DL COMPACT><DD> (Greek Mythology.) the hunter who saw Artemis (Diana) bathing. In anger she changed him into a stag, and his own dogs tore him to pieces. </DL>
<A NAME="actbattery">
<B>ACT battery,</B><DL COMPACT><DD> a group of tests similar to the College Boards given to a student applying for admission to a college, covering different fields of knowledge, and also a profile covering the achievements, goals, and special interests of the student. </DL>
<A NAME="actdrop">
<B>act-drop, </B>noun.<DL COMPACT><DD> (in a theater) a curtain which is lowered between acts. </DL>
<A NAME="actegratuit">
<B>acte gratuit,</B><DL COMPACT><DD> (French.) an act performed without reason or cause; a gratuitous act. <BR> <I>Ex. The hero ... behaves like a personification of Gide's acte gratuit ("an action motivated by nothing ... born of itself") (Time).</I> </DL>
<A NAME="acth">
<B>ACTH, </B>noun.<DL COMPACT><DD><B> 1. </B>adrenocorticotropic hormone (a hormone of the pituitary gland that stimulates the cortex of the adrenal gland to produce other hormones). <DD><B> 2. </B>this hormone obtained from animals, used in treating arthritis, rheumatic fever, and certain other disorders; corticotropin. </DL>
<A NAME="actian">
<B>Actian, </B>adjective.<DL COMPACT><DD> of or having to do with Actium, an ancient town and promontory in western Greece. </DL>
<A NAME="actiangames">
<B>Actian games,</B><DL COMPACT><DD><B> 1. </B>games held from remote antiquity at Actium in honor of Apollo. <DD><B> 2. </B>a later series of games founded by the Roman emperor Augustus in commemoration of his naval victory near Actium over Antony and Cleopatra (September 2, 31 B.C.). </DL>
<B>actin, </B>noun.<DL COMPACT><DD> a protein component of muscle fibers that acts with another protein, myosin, in muscle contraction. Actin exists in a globular and a fibrous form. </DL>
<A NAME="actinal">
<B>actinal, </B>adjective.<DL COMPACT><DD><B> 1. </B>having to do with the side of a radiate animal that contains the mouth; oral. <DD><B> 2. </B>having tentacles or rays. adv. <B>actinally.</B> </DL>
<A NAME="acting">
<B>acting, </B>adjective, noun.<DL COMPACT><DD><I>adj. </I> <B>1. </B>temporarily taking another's place and doing his duties; substitute. <BR> <I>Ex. While the governor was sick, the lieutenant governor was acting governor.</I> <DD><B> 2. </B>specially prepared for actors' use (provided with full stage directions, etc.). <BR> <I>Ex. the acting copy of a play.</I> <DD><I>noun </I> the occupation of an actor or actress; the art or fact of playing a part on the stage, in motion pictures, on television, or over the radio. </DL>
<A NAME="actinia">
<B>actinia, </B>noun, pl. <B>-iae</B> , <B>-ias.</B> <B>=sea anemone.</B></DL>
<B>actinic, </B>adjective.<DL COMPACT><DD><B> 1. </B>producing chemical changes by radiation. <DD><B> 2. </B>of actinism. adv. <B>actinically.</B> </DL>
<A NAME="actinicrays">
<B>actinic rays,</B><DL COMPACT><DD> rays of radiant energy, especially from the sun, that produce chemical change. Actinic rays are important in photography. They include green, blue, violet, and ultraviolet rays, X rays, gamma rays, and infrared radiation. </DL>
<A NAME="actinide">
<B>actinide, </B>noun.<DL COMPACT><DD> one of the actinides (series of heavy, radioactive metallic elements with atomic numbers 89 or 90 through 103). </DL>
<A NAME="actinides">
<B>actinides, </B>noun pl.<DL COMPACT><DD> the series of chemical elements extending from actinium (atomic number 89) or thorium (atomic number 90) to lawrencium (atomic number 103); actinium, thorium, protactinium, uranium, neptunium, plutonium, americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, nobelium, and lawrencium. The properties of these elements differ only slightly with increasing atomic number. </DL>
<A NAME="actinideseries">
<B>actinide series,</B><DL COMPACT><DD> the actinides. </DL>
<A NAME="actiniform">
<B>actiniform, </B>adjective.<DL COMPACT><DD> (Zoology.) having a radiated form, as the sea anemone does. </DL>
<A NAME="actinism">
<B>actinism, </B>noun.<DL COMPACT><DD> (Especially U.S.) that action or property in radiant energy that produces chemical changes, for example in photography. </DL>
<A NAME="actinium">
<B>actinium, </B>noun.<DL COMPACT><DD> a radioactive, metallic chemical element somewhat like radium, found in pitchblende after uranium has been extracted or obtained from radium by bombardment with neutrons. </DL>
<A NAME="actiniumemanation">
<B>actinium emanation,</B><B>=actinon.</B></DL>
<A NAME="actiniumk">
<B>actinium K,</B><DL COMPACT><DD> the name originally given to element number 87 by its discoverer, who changed it to <I>francium</I> in 1947. </DL>
<A NAME="actiniumseries">
<B>actinium series,</B><DL COMPACT><DD> the series of isotopes produced by radioactive decay of actinium. </DL>
<A NAME="actinobacillosis">
<B>actinobacillosis, </B>noun.<DL COMPACT><DD> a disease of domestic animals, especially cattle, similar to actinomycosis. </DL>
<A NAME="actinogram">
<B>actinogram, </B>noun.<DL COMPACT><DD> a record made by an actinograph. </DL>
<A NAME="actinograph">
<B>actinograph, </B>noun.<DL COMPACT><DD> a recording actinometer. </DL>
<A NAME="actinographic">
<B>actinographic, </B>adjective.<DL COMPACT><DD> of or measured by an actinograph. </DL>
<A NAME="actinography">
<B>actinography, </B>noun.<DL COMPACT><DD> the recording of intensities of radiant energy by means of an actinograph. </DL>
<A NAME="actinoid">
<B>actinoid, </B>adjective.<DL COMPACT><DD> having the form of rays; radiated. A starfish is actinoid. </DL>
<A NAME="actinolite">
<B>actinolite, </B>noun.<DL COMPACT><DD> a green variety of amphibole containing iron, usually occurring in needle-shaped crystals. </DL>
<A NAME="actinology">
<B>actinology, </B>noun.<DL COMPACT><DD> the branch of physics dealing with the chemical action of light. </DL>
