Britannica Dictionary definition of ON
1
a
:
touching and being supported by the top surface of (something)
b
:
to a position that is supported by (something)
c
—
used to indicate the part or object by which someone or something is supported
2
—
used to say that something is attached to something
3
—
used to indicate where someone or something is hit or touched
-
I bumped my head on a low branch.
-
He slapped me on the hand.
-
She kissed him on the cheek.
4
a
—
used to indicate the surface or part where something is seen or located
b
—
used to say that something (such as jewelry) is being worn by someone
5
:
near or close to (something or someone)
6
—
used to indicate the location or position of something or someone
-
Our house is on the left.
-
There is a garden on the side of the house.
-
We saw cows and chickens on the farm.
-
He lives on Main Street.
-
on page 102 in/of the book
-
Which side is it on?
7
—
used to indicate the time when something happened or will happen
-
We met on July 24th.
-
On my way home [=while I was going home], I saw a car accident.
-
(formal) On the morning of July 24th, the suspect left his house at 8:15 a.m.
-
I would like the report on or before July 24th.
-
The TV station gives news every hour on the hour. [=at 6:00, 7:00, 8:00, etc.]
-
The project was finished on schedule/time. [=when it was supposed to be finished]
8
:
immediately after (something)
9
—
used to indicate the subject of something
-
a book on [=about] North American birds
-
a discussion on current events
-
Let's reflect on [=upon] the poem for a moment.
-
a test on parts of speech
10
a
—
used to indicate the device or instrument that is used to do something
b
—
used to say that someone is using a telephone, computer, etc.
-
They talked on the phone for hours.
-
She was on the phone when I went to her office.
-
He has been on the computer all night.
c
—
used to describe the device, system, etc., that is used for seeing something, hearing something, etc.
-
It's the best show on television.
-
I heard that song on the radio.
-
the display on the computer screen
-
a Web site on the Internet
-
I have the movie on DVD.
11
—
used to indicate a source of something (such as money, food, information, or energy)
-
She lives on a small salary.
-
The family lives on welfare.
-
They make their living on [=off] tourism.
-
They profited on [=from] the sale of the house.
-
The animal feeds on insects.
-
I lived on cereal [=I ate a lot of cereal regularly] in my college years.
-
The machine runs on diesel fuel.
-
The story is based on fact.
12
—
used to indicate the vehicle or animal by which someone or something is moved from one place to another
13
—
used to say that you have something in your possession at a particular time
-
I only have $10 on me.
-
He had a knife on him.
14
—
used to indicate the state of something
15
—
used to indicate an activity that someone did or is now doing
-
She did well on the exam/test.
-
The band is currently on tour.
-
He is off/away on a trip/vacation.
-
She is on a diet.
-
The officers are on duty.
16
—
used to indicate something (such as a medicine or drug) that a person or animal is using
-
He used to be on drugs, but he's off them now.
-
(informal) What (drugs) is she on?
-
They put the dog on antibiotics.
17
—
used to indicate the person or thing that is responsible for something
18
a
—
used to indicate the person or thing that something is directed toward
-
The deadline was creeping up on us. [=the deadline was getting closer]
-
an attack on religion
-
He is working on [=at] his skiing.
-
They are still working on the problem.
-
They made a down payment on the house.
-
He pulled a gun on me.
-
He turned his back on her and walked away.
-
a ban on smoking
-
Her eyes were on the road. [=she was watching the road]
b
—
used to say that someone has been affected by something
19
—
used after an adjective to indicate the thing that a statement relates to
-
I am short on cash. [=I don't have much cash]
-
Opinions are divided on this issue.
-
(Brit) Sales are up on last year's but down on those of previous years.
20
:
as stated or shown by (someone or something)
-
I have it on good authority [=a trustworthy person has told me] that the company will be relocating.
-
(Brit) On [=according to] these estimates, we'll be out of debt soon.
21
—
used to indicate that someone or something is included as part of a team, list, etc.
-
She served on the jury/committee/board.
-
He is on the team.
-
That dish is no longer on the menu.
-
His name was on the list.
22
—
used to say that someone or something has an advantage
-
She has three inches in height on me. [=she is three inches taller than I am]
-
The team has a 3-game lead on last year's champions.
-
She is very talented but has nothing on [=has no advantage over] her brother who is an even better singer.
23
chiefly US
—
used to say that someone is playing or performing well
on about
British, informal + disapproving
on at
British, informal
1
:
asking (someone) for something repeatedly and in a way that is annoying
2
:
asking or telling (someone) to do something repeatedly and in a way that is annoying
on it
:
actively dealing with a problem, job, etc.
2
on
/ˈɑːn/
adverb
Britannica Dictionary definition of ON
1
a
—
used to indicate that something is attached to, covering, or supported by something else
b
—
used to describe something that is being worn by someone
-
He put on his coat and went outside.
-
You can keep your shoes on.
-
What did he have on? [=what was he wearing?]
-
He had on a black shirt and jeans.
2
—
used to indicate movement forward
3
a
—
used to indicate that an activity, event, or condition continues
-
The argument went on for weeks.
-
He worked on without a break.
-
Please read on for information about our products.
-
The teams played on in the snow.
-
She rambled on (and on) about her lazy husband.
-
From now on [=from this point in time forward], be sure to double-check your answers.
-
From here on (out), things should get easier. = From this point on, things should get easier.
c
:
at a more advanced time
:
at a later time
4
:
from one person or thing to another
5
a
—
used to indicate that something is operating, flowing, etc.
b
—
used to indicate that something is being heated, prepared, etc.
-
I'll put the kettle/tea/coffee on (to boil). [=I will put the kettle/tea/coffee on the stove to make it warmer]
-
I've got coffee on, if you're interested.
6
:
in or into a train, bus, etc.
3
on
/ˈɑːn/
adjective
Britannica Dictionary definition of ON
1
not used before a noun
:
attached to or covering something
2
not used before a noun
:
performing or speaking in public
-
The band will be on in 10 minutes.
-
Mr. President, you are on in two minutes. [=you will be giving your speech in two minutes]
3
not used before a noun
:
working at a job
4
a
not used before a noun
:
operating or flowing
b
:
in a position that starts the flow of electricity, water, etc.
5
not used before a noun
a
:
taking place or happening
b
:
doing something as planned
6
not used before a noun
:
being broadcast on television or radio
-
The show is on at 8 p.m.
-
The game is on tonight.
-
My favorite show is on.
7
not used before a noun,
chiefly US
—
used to say that you are able to do something well at a particular time
not on
British, informal
1
:
not acceptable or proper
you're on
informal
—
used to say that you accept a bet or challenge