1
a
used as a function word to indicate position in contact with and supported by the top surface of
the book is lying on the table
b
used as a function word to indicate position in or in contact with an outer surface
the fly landed on the ceiling
I have a cut on my finger
paint on the wall
c
used as a function word to indicate position in close proximity with
a village on the sea
stay on your opponent
d
used as a function word to indicate the location of something
on the left
on the south side of the house
on the farm
2
a
used as a function word to indicate a source of attachment or support
on a string
stand on one foot
hang it on a nail
b
used as a function word to indicate a source of dependence
you can rely on me
feeds on insects
lives on a pension
c
used as a function word to indicate means of conveyance
on the bus
d
used as a function word to indicate presence in the possession of
had a knife on him
3
used as a function word to indicate a time frame during which something takes place
a parade on Sunday
or an instant, action, or occurrence when something begins or is done
on cue
on arriving home, I found your letter
news on the hour
cash on delivery
4
archaic : of
5
a
used as a function word to indicate manner of doing something
often used with the
on the sly
keep everything on the up-and-up
b
used as a function word to indicate means or agency
cut myself on a knife
talk on the telephone
c
used as a function word to indicate a medium of expression
on stage
best show on television
6
a(1)
used as a function word to indicate active involvement in a condition or status
on the increase
on the lookout
(2)
: regularly using or showing the effects of using
on drugs
b
used as a function word to indicate involvement or participation
on tour
on the team
on duty
c
used as a function word to indicate inclusion
put it on the agenda
d
used as a function word to indicate position or status in proper relationship with a standard or objective
on schedule
7
a
used as a function word to indicate reason, ground, or basis (as for an action, opinion, or computation)
I have it on good authority
on one condition
the interest will be 10 cents on the dollar
b
used as a function word to indicate the cause or source
profited on the sale of stock
c
used as a function word to indicate the focus of obligation or responsibility
drinks are on the house
put the blame on me
8
a
used as a function word to indicate the object of collision, opposition, or hostile action
bumped my head on a limb
an attack on religion
pulled a gun on me
b
used as a function word to indicate the object with respect to some disadvantage, handicap, or detriment
has three inches in height on me
a 3-game lead on the second-place team
the joke's on me
9
a
used as a function word to indicate destination or the focus of some action, movement, or directed effort
crept up on him
feast your eyes on this
working on my skiing
made a payment on the loan
b
used as a function word to indicate the focus of feelings, determination, or will
have pity on me
keen on sports
a curse on you
c
used as a function word to indicate the object with respect to some misfortune or disadvantageous event
the crops died on them
d
used as a function word to indicate the subject of study, discussion, or consideration
a book on insects
reflect on that a moment
agree on price
e
: with respect to
go light on the salt
short on cash
10
used as a function word to indicate reduplication or succession in a series
loss on loss
trouble on trouble

on

2 of 7

adverb

1
a
: in or into a position of contact with an upper surface especially so as to be positioned for use or operation
put the plates on
b
: in or into a position of being attached to or covering a surface
especially : in or into the condition of being worn
put his new shoes on
2
a
: forward or at a more advanced point in space or time
went on home
later on
b
: in continuance or succession
rambled on
and so on
3
: into operation or a position permitting operation
switched the light on

on

3 of 7

adjective

1
: engaged in an activity or function (such as a dramatic role)
2
a(1)
: being in operation
The radio is on.
(2)
: placed so as to permit operation
The switch is on.
b
: taking place or being broadcast
The game is on.
3
: aware of something
usually used with to
My boss was on to me.
4
: intended, planned
has nothing on for tonight
5
British : talking or harping incessantly
used with about
6
chiefly British : regarded as possible or feasible
usually used in negative constructions
7
a
: engaged in or as if in a performance
The comedian was always on.
b
: being at a high level of performance

ON

4 of 7

abbreviation

variants or Ont
Ontario

-on

5 of 7

noun suffix (1)

: chemical compound not a ketone or other oxo compound
parathion

-on

6 of 7

noun suffix (2)

1
: subatomic particle
nucleon
2
a
: unit : quantum
photon
magneton
b
: basic hereditary component
cistron
operon

-on

7 of 7

noun suffix (3)

: noble gas
radon

Examples of on in a Sentence

Preposition There is a lot of frosting on the cake. books on sports heroes are my favorite reading matter Adverb We're far on with our project. I'll come by to help you later on. Adjective The lid is on tight. The band will be on in 10 minutes. He is on tomorrow from 6 a.m. to 6 p.m.
Recent Examples on the Web
Preposition
The romantic duo comes across as blank slates on which audiences may project themselves, nostalgically bathed by summer sunsets and moonlit nights, nicely supplied by lighting designer Ben Stanton. Frank Rizzo, Variety, 15 Mar. 2024 Granlund had the puck on his stick to the right of the Sharks’ net when he was checked against the boards by Rust. Curtis Pashelka, The Mercury News, 15 Mar. 2024 Stapleton will be heading to Saturday Night Live as musical guest on April 13, with Ryan Gosling as host, marking the third time he’s served as musical guest on the show. Rania Aniftos, Billboard, 14 Mar. 2024 Rajskub played Chloe O’Brian on the long-running 24 drama and also starred in the comedy Night School with Kevin Hart and Tiffany Haddish and Mayfield Games with Mira Sorvino. Etan Vlessing, The Hollywood Reporter, 14 Mar. 2024 The event was held at the Polo Lounge at the Beverly Hills Hotel on Saturday. Angel Saunders, Peoplemag, 14 Mar. 2024 Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from celebrity news to compelling human interest stories. Esme Mazzeo, Peoplemag, 3 Mar. 2024 Despite mass viewership around the globe, not even a week after launch, Avatar: The Last Airbender has lots its #1 spot on Netflix’s Top 10 list, at least in the US, where another popular show has surged above it. Paul Tassi, Forbes, 2 Mar. 2024 While on a visit to Montreal, Vermette was driving by a field of septic tanks. Jazz Tangcay, Variety, 2 Mar. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'on.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

Preposition, Adverb, and Adjective

Middle English an, on, preposition & adverb, from Old English; akin to Old High German ana on, Greek ana up, on

Noun suffix (1)

International Scientific Vocabulary, alteration of -one

Noun suffix (2)

from -on (in ion)

Noun suffix (3)

New Latin, from -on (in argon)

First Known Use

Preposition

before the 12th century, in the meaning defined at sense 1a

Adverb

before the 12th century, in the meaning defined at sense 1a

Adjective

circa 1541, in the meaning defined at sense 1

Time Traveler
The first known use of on was before the 12th century

Dictionary Entries Near on

Cite this Entry

“On.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/on. Accessed 19 Mar. 2024.

Kids Definition

on

1 of 3 preposition
(ˈ)ȯn How to pronounce on (audio)
(ˈ)än
1
a
: in contact with and supported by
the book on the table
b
: in a position in contact with or near
a fly on the wall
a town on the river
c
used to indicate the location of something
on the other side of the house
on the right
2
a
used to indicate means of being attached or supported
on a string
stood on one foot
hang your coat on the peg
you can rely on me
lives on insects
b
used to indicate means of being carried
rode on a horse
went on the bus
have only five dollars on me
3
used to indicate a time or an instance when something takes place
on arriving home, I found your letter
arrived on Monday
news on the hour
4
a
used to indicate the way something is done
told her on the sly
b
used to indicate what something is done with or done by
cut on broken glass
talk on the phone
type on a keyboard
displayed on a TV screen
5
a
: involved with or participating in : busy with
on a committee
on tour
b
: in a state or process of
on fire
on the increase
c
: in keeping with a goal or objective
on schedule
6
a
used to indicate a reason or basis
on one condition
interest of 10 cents on the dollar
b
used to indicate who or what is responsible
this treat is on me
blamed it on the weather
7
used to indicate someone or something an action or feeling is directed toward
was creeping up on us
have pity on me
the joke's on you
8
a
: concerning, about
a book on cats
agree on price
b
: with respect to
go light on the salt
short on cash
9
: following in series
loss on loss

on

2 of 3 adverb
ˈȯn,
ˈän
1
: in or into contact with a surface
put the kettle on
has new shoes on
2
: forward in space, time, or action
went on home
on came the storm
getting on in years
3
: from one to another
pass the word on
and so on
4
: into operation or a position allowing operation
turn the light on

on

3 of 3 adjective
ˈȯn,
ˈän
1
: doing an activity (as a role in a play)
you're on next
2
a
: being in operation
the radio is on
b
: set so as to permit operation
the switch is on
c
: taking place or being broadcast
the game is on
3
: having been planned
has nothing on for tonight

Medical Definition

on

preposition
: regularly using or showing the effects of using
is on an ACE inhibitor to control hypertension
was on drugs for two years before entering rehab

More from Merriam-Webster on on

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