First Known Use: 14th century
Dictionary
1act
noun \ˈakt\
: something that is done
: a law made by a group of legislators
: one of the main divisions of a play or opera
Full Definition of ACT
1
a : the doing of a thing : deed b : something done voluntarily
2
: a state of real existence rather than possibility
3
: the formal product of a legislative body : statute; also : a decision or determination of a sovereign, a legislative council, or a court of justice
4
: the process of doing : action <caught in the act>
5
often capitalized : a formal record of something done or transacted
6
: one of the principal divisions of a theatrical work (as a play or opera)
7
a : one of successive parts or performances (as in a variety show or circus) b : the performer or performers in such an act c : a performance or presentation identified with a particular individual or group d : the sum of a person's actions or effects that serve to create an impression or set an example <a hard act to follow>
8
: a display of affected behavior : pretense
— into the act or in on the act
: into an undertaking or situation as an active participant
See act defined for English-language learners
See act defined for kids
ADVERTISEMENT
Origin of ACT
Middle English, partly from Latin actus doing, act, from agere to drive, do; partly from Latin actum thing done, record, from neuter of actus, past participle of agere — more at agent
2act
verb
: to do something : to take action
: to behave in a particular way
: to behave in a way that is not sincere or honest
Full Definition of ACT
transitive verb
2
3
: to play the part of as if in a play <act the man of the world>
4
: to behave in a manner suitable to <act your age>
intransitive verb
1
a : to perform on the stage b : to behave as if performing on the stage : pretend
2
: to take action : move <think before acting> <acted favorably on the recommendation>
3
: to conduct oneself : behave <act like a fool>
4
: to perform a specified function : serve <trees acting as a windbreak>
5
: to produce an effect : work <wait for a medicine to act>
6
of a play : to be capable of being performed <the play acts well>
7
: to give a decision or award <adjourned without acting on the bill>
— act·abil·i·ty \ˌak-tə-ˈbi-lə-tē\ noun
— act·able \ˈak-tə-bəl\ adjective
See act defined for English-language learners
First Known Use of ACT
1590
3act
abbreviation
Definition of ACT
1
active
2
actor
3
actual
Other Performing Arts Terms
1ACT
abbreviation
Definition of ACT
1
Action for Children's Television
2
Association of Classroom Teachers
3
Australian Capital Territory
See ACT defined for English-language learners
Other Education Terms
2ACT
trademark \ˌā-ˌsē-ˈtē\
Definition of ACT
—used for a standardized achievement test to evaluate suitability for college admission
Other Education Terms
ACT[2] Defined for Kids
1act
noun \ˈakt\
Definition of ACT for Kids
1
: something that is done : deed <an act of bravery>
2
: a law made by a governing body
3
: a main division of a play
4
: one of the performances in a show <a juggling act>
5
: an insincere way of behaving <Her crying was just an act.>
2act
verb
act·edact·ing
Definition of ACT for Kids
1
: to do something : move <It's important to act quickly in an emergency.>
2
: to behave oneself in a certain way <He's been acting strangely.>
3
: to perform as a character in a play <Both stars agreed to act in the movie.>
4
: to perform a certain function <She'll act as our guide.>
5
: to have a result : make something happen : work <The medicine acts on the heart.>
— act up
: to behave badly
Learn More About ACT
ADVERTISEMENT
Seen & Heard
What made you want to look up act? Please tell us where you read or heard it (including the quote, if possible).