act meaning
EN
[ækt] [æk] [-ækt] 
US WAct
- Act or ACT may mean:
- Act (band), a British band
- Act (document), a document recording the legality of a transaction or contract
- Act of Parliament, Act of Congress or Act of Tynwald, a statute or law passed by a legislature
- Act (drama), a segment of a performance, such as a play or opera
- Act or Acts, an obsolete name for the defence of theses at the University of Oxford and University of Cambridge
- Act! CRM, a customer relationship management software
- Acting, action of an actor in a theatrical performance
- Acting (law), in law when someone is acting in a position of higher expenses
EN ACT 
- NounPLacts
- NC Something done, a deed.
- an act of goodwill
- OBS NU Actuality.
- NC A product of a legislative body, a statute.
- But was it responsible governance to pass the Longitude Act without other efforts to protect British seamen? Or might it have been subterfuge—a disingenuous attempt to shift attention away from the realities of their life at sea.
- The process of doing something.
- He was caught in the act of stealing.
- NC A formal or official record of something done.
- NC A division of a theatrical performance.
- “H'm !” he said, “so, so—it is a tragedy in a prologue and three acts. I am going down this afternoon to see the curtain fall for the third time on what [...] will prove a good burlesque ; but it all began dramatically enough. It was last Saturday […] that two boys, playing in the little spinney just outside Wembley Park Station, came across three large parcels done up in American cloth. […]”
- NC A performer or performers in a show.
- Which act did you prefer? The soloist or the band?
- NC Any organized activity.
- The minute you let it be known you're planning a sales campaign everybody wants to get into the act.
- NC A display of behaviour.
- A thesis maintained in public, in some English universities, by a candidate for a degree, or to show the proficiency of a student.
- NC A display of behaviour meant to deceive.
- to put on an act
- NC Something done, a deed.
- VerbSGactsPRactingPT, PPacted
- VI To do something.
- If you don't act soon, you will be in trouble.
- OBS VT To do (something); to perform.
- VI To perform a theatrical role.
- I started acting at the age of eleven in my local theatre.
- VI To behave in a certain way.
- He's acting strangely - I think there's something wrong with him.
- (copulative) To convey an appearance of being.
- He acted unconcerned so the others wouldn't worry.
- To do something that causes a change binding on the doer.
- act on behalf of John
- VI (construed with on or upon) To have an effect (on).
- High-pressure oxygen acts on the central nervous system and may cause convulsions or death.
- Gravitational force acts on heavy bodies.
- VT To play (a role).
- He's been acting Shakespearean leads since he was twelve.
- VT To feign.
- He acted the angry parent, but was secretly amused.
- (mathematics, intransitive, construed with on or upon, of a group) To map via a homomorphism to a group of automorphisms (of).
- This group acts on the circle, so it can't be left-orderable!
- OBS VT To move to action; to actuate; to animate.
- VI To do something.
- More Examples
- Used in the Middle of Sentence
- For example, Coventry twinned with Dresden as an act of peace and reconciliation, both cities having been heavily bombed during the war.
- Great George was acting up, so his master sent him to a slave breaker.
- Methylene blue (MB, methylthioninium chloride) is a phenothiazine that crosses the blood brain barrier and acts as a redox cycler.
- Used in the Beginning of Sentence
- Act your age and stop fiddling with that pen - you’re showing us up.
- Used in the Ending of Sentence
- I really got a kick out of that clown's juggling act.
- Earlier the gentleman from California (Mr. Cardoza) got up on the floor, and he was upset that somebody had said that the underlying bill would eviscerate the Endangered Species Act.
- She denied it but she had been spotted in the act.
- Used in the Middle of Sentence
Definition of act in English Dictionary
- Part-of-Speech Hierarchy
- Nouns
- Countable nouns
- Singularia tantum
- Uncountable nouns
- Uncountable nouns
- Countable nouns
- Verbs
- Copulative verbs
- Intransitive verbs
- Transitive verbs
- Copulative verbs
- Nouns
Source: Wiktionary
Grammatically, this word "act" is a noun, more specifically, a countable noun and a singularia tantum. It's also a verb, more specifically, a copulative verb, an intransitive verb and a transitive verb.