on

1 preposition

1 touching or being supported by a particular surface: The plate's on the table. | You have mud on your shoes. | The answer is written on page 25.

2 hanging from, supported by or connected to a particular thing: Stand on one foot. | pictures stuck on the wall | a ball on a string

3

a) in a particular place, building or area of land: Several bombs landed on the runway. | He grew up on a ranch in California.

b) AmE in a particular road: We live on Mulberry Drive. | I met Amy on the street the other day.

4 in a particular direction: On my right sat the Chancellor. | As the troops marched on the city, the leaders planned their escape.

5 used to show the person or thing affected by an action or someone's behaviour: a tax on cigarettes | The divorce has had a particularly bad effect on the children.

6 on one of the sides of something such as a river or road: a cafe on the river | a beautiful village on the Austrian border | trees on both sides of the street

7 on Friday/August 2nd/my birthday at some time during a particular day: They arrive on Tuesday. | I was born on July 1st.

8 about a particular subject: a book on India | advice on what to wear

9 in a bus, train, aircraft etc: Everyone on the plane was frightened. | He managed to be on the first train back to London.

—see also: on foot foot 1 (2), on horseback horseback

10 used to say what food someone needs to survive, what fuel 1 (1) something needs to operate etc: We can't live on rice and water forever. | Many cars nowadays run on lead free petrol.

11 used to say what money people use to live, the amounts of money someone earns etc: Some families in the ghettos have been on welfare all their lives. | People on high salaries should pay more tax.

12 informal used to say that someone takes a particular drug or medicine: Since she's been on Prozac she's been a different person.

13 on the radio/telephone using a radio or telephone: Shut up! I'm on the phone.

14 on a trip/journey etc during a trip, journey etc: I met several people on the voyage. | On my way to work the car broke down.

15 used to say what has been used to do something: Phil had torn his shirt on a nail. | It's amazing what you can do on these new word processors.

16 formal immediately after something has happened or after someone has done something: on doing sth: On hearing the news of the air attack most foreigners headed for the border. | on arrival/sb's return etc: On arrival at reception, guests should sign the visitors' book. | on sth: On the general's command, all soldiers must salute.

17 used to say that someone is a member of a team, organization etc: What team did you say your boyfriend was on?

18 compared with another person or thing: This essay is a definite improvement on your last one. | Sales are 10% up on last year.

19 have/carry etc sth on you informal to have a particular thing in your pocket, your bag etc: How much cash do you have on you?

20 spoken used to say that someone will pay for something such as a drink, a meal etc: Drinks are on Harold!

21 informal if a machine stops, breaks etc on you, it stops or breaks while you are using it: Suddenly the telephone went dead on me.

2 adjective, adverb (not before noun)

1 used to say that someone continues to do something or something continues to happen, without stopping: play/read/talk etc on (=to continue playing, reading etc): Both teams managed to play on into overtime, despite the blistering heat. | carry/keep/go on etc doing sth: If you keep on eating like that you'll need to diet. | carry/keep/go on etc: Carry on. You're doing very well.

2 if you move, walk etc on, you move forward to a particular place: If you walk on a little, you can see the coast. | You can have your letters sent on to you at your new address. | straight on: Keep straight on and turn left at the bank.

3 used to say that something happens at a time that is before or after another time: earlier/later on: Later on we learned that he got back to France safely. | from then on/from that day on etc: From that moment on I never believed a word she told me.

4 if you have something on, you are wearing it: Put your coat on. It's freezing outside. | The poor child had absolutely nothing on.

5 in a bus, train, aircraft etc: The bus stopped and everyone rushed to get on.

6 if a machine, light etc is on, it is operating: Who left the hot water faucet on? | The TV's on but nobody seems to be watching it.

—opposite off 1 (4)

7 if a film, TV programme etc is on, it is being broadcast or shown at a theatre: That new sitcom is on tonight.

8 if an event is on, it is happening or will still happen: There's a jazz festival on in Vancouver this week. | Are you sure the party's on for tonight?

9 have a lot on informal to be very busy: We don't have much on at the moment. I could see you tomorrow.

10 be on at sb informal to keep asking someone to do something, so that they become annoyed: Mildred's been on at him to fix that cupboard for weeks now.

11 be/go on about sth informal BrE to keep talking about something, in a way that is boring: Will you stop going on about that goal! It was definitely a penalty.

12 on and off also off and on if you do something during a period of time on and off, you do it for several short periods in that time but not continually: He's been smoking for 10 years now, on and off.

13 it's not on spoken BrE used to say that you do not think something is socially acceptable or reasonable: It's not on, is it? Leaving your children alone like that.

14 head on/full on if two things hit each other head on, they hit the front part of each other, usually very hard: Both cars skidded, crashing head on at 80 miles an hour.

15 if an actor is on, they are performing: You're on in two minutes.