Definition of moment noun from the Oxford Advanced Learner's Dictionary

Oxford3000

moment

noun
ˈməʊmənt
 
; ˈmoʊmənt
 
 
1 a very short period of timeCould you wait a moment, please?One moment, please(= Please wait a short time).He thought for a moment before replying.I'll be back in a moment.We arrived not a moment too soon(= almost too late).Moments later(= a very short time later), I heard a terrible crash. see also senior moment2 [singular] an exact point in timeWe're busy at the moment(= now).I agreed in a moment of weakness.At that very moment, the phone rang.From that moment on, she never felt really well again.3 [countable] a particular occasion; a time for doing somethingI'm waiting for the right moment to tell him the bad news.That was one of the happiest moments of my life.Have I caught you at a bad moment?
Idioms

(at) any moment (now)

very soon
Hurry up! He'll be back any moment now.

at this moment in time

(informal) now, at the present timeAt this moment in time, I don't know what my decision will be.

for the moment/present

for now; for a short time
This house is big enough for the moment, but we'll have to move if we have children.

have its/your moments

to have short times that are better, more interesting, etc. than others
The job isn't exciting all the time, but it has its moments.I found the play rather boring, but it had its moments.

the moment of truth

a time when somebody/something is tested, or when important decisions are made
The moment of truth is when the trainee pilots take over the controls of the plane.

the moment (that)…

as soon as…
I want to see him the moment he arrives.The moment she walked through the door I thought she looked different.

not for a/one moment

certainly not; not at all
I don't think for a moment that she'll accept but you can ask her.

of moment

very important
matters of great moment

of the moment

(of a person, a job, an issue, etc.) famous, important and talked about a lot nowShe's the fashion designer of the moment.
more at the evil hour/day/moment at evil, just a minute/moment/second at just adverb, the last minute/moment at last det.
Idioms
see
at a moment's notice at notice n.
, the psychological moment at psychological, on the spur of the moment at spur n., wait a minute/moment/second at wait v.